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I have been baking these Monster Cookies for almost two decades, they are THE BEST! Pillowy soft, packed with peanut butter, oats, chocolate, and all your favorite mix-ins, they are are scarily good.

A stack of trail mix monster cookies with peanuts and chocolate

If you’ve never tried monster cookies, you’re in for a treat!

Thanks to the plethora of mix-ins and peanut butter flavor, this is my version of the ultimate monster cookie recipe.

  • Monster cookies are supremely ooey-gooey, thick, and chewy.
  • They’re jam-packed with bits and bites of chocolate and peanut butter in various forms (chips, candies, and straight-up PB).
  • They’re incredibly versatile. Change up the mix-ins as you please, or swap in a different nut butter.

Perfect for kids and adults alike, this cookie recipe is a keeper!

easy monster cookie recipe for chewy soft cookie on a plate with a bite taken out

5 Star Review

“These are the BEST monster cookies I have ever made! They are crunchy and soft at the same time and have the perfect amount of peanut butter. I will be making these for years to come!”

— Jessie —

About These Monster Cookies

While the true origin and inventor of monster cookies are unknown, I like to think that monster cookies are called monster cookies because they’re the most epic, monstrous mashup of every cookie you love in one tasty little package.

Also, they’re scarily delicious!

I was introduced to these best-ever monster cookies by my “work friend,” Lindsey.

They’re one of her family’s most treasured recipes, and you can tell. They’re perfect in that special way that tastes of the fine-tuning of generations.

Once you try them, I know you’ll be baking them for decades to come yourself.

monster cookies with m&ms, oats, and peanut butter

How to Make Monster Cookies

These chewy monster cookies are made of classic cookie ingredients (flour, butter, sugar, vanilla), oats, peanut butter, and an array of fun mix-ins.

I made a few tweaks to put this recipe above the nutritional profile of other not-so-healthy cookies (the Pioneer Woman monster cookies, for example), such as using whole wheat flour.

The Ingredients

  • Butter. The key to a perfectly textured monster cookie. It’s 100% worth it to use the butter in this recipe, I promise.
  • Sugar. A combination of brown sugar and granulated sugar creates just the right texture and makes the cookies moist and chewy.
  • Peanut Butter. Critical to any original monster cookie recipe. Creamy peanut butter (shelf-stable or natural peanut butter) adds oodles of rich flavor and complements the oats and other mix-ins. Peanut butter is also rich in protein and potassium.

Substitution Tip

If you need a monster cookie recipe without peanut butter, you could swap in a different creamy nut butter or try sun butter (heads up: sun butter will turn your cookies a little green).

  • Pure Vanilla Extract. One of my favorite ingredients to add to any cookie recipe. The flavor is delicious here!
  • Whole Wheat Flour. I swapped in whole wheat flour to make these cookies slightly better for you, and the change is imperceptible.

Substitution Tip

You can swap the whole wheat flour for all-purpose flour if you prefer.

  • Rolled Oats. Not only do the oats add a slightly chewy texture and nutty flavor, but they also bring in some protein and fiber. Plus, they’re naturally gluten free. (Love oats in cookies? Don’t miss my Oatmeal Cookies.)
  • Mix-ins. As far as mix-ins go, monster cookies traditionally call for chocolate chips and M&M candies, but I love adding peanut butter chips to the mix too. The double hit of PB is the secret to making these the best, most addictive cookies you’ll try. For another fun cookie with lots of mix-ins, check out Trail Mix Cookies.

The Directions

monster cookie recipe ingredients in a bowl
  1. Cream the butter and sugars until fluffy with a hand mixer.
stirring together monster cookie dough recipe in a bowl
  1. Beat in the peanut butter and other wet ingredients.
monster cookie dough in a bowl for mix ins
  1. Add the baking soda and salt, then slowly add the flour.
monster cookie dough with mix ins in a large bowl
  1. Beat in the oats. Stir in your mix-ins, and chill the dough.
monster cookies with oats and m&ms rolled on a baking sheet
  1. Scoop and bake the monster cookies at 350 degrees F for 10 minutes. You can tell if monster cookies are done by checking if they’re golden brown.
soft monster cookie dough balls on a baking sheet
  1. Let them rest on the cookie sheet for a few minutes (letting them sit on the sheet to firm up a bit will make sure your monster cookies don’t fall apart). DIG IN!

A Note on Cookie Size

This recipe will yield a large batch of 36-40 small cookies. I prefer baking my cookies bite-sized (so I can justify eating more of them), but if you prefer giant monster cookies, you can certainly scoop the dough larger and extend the total time baking by a few minutes.

the BEST soft and chewy monster cookies on a plate

Storage Tips

  • To Store. Store leftover cookies in an airtight storage container for up to 1 week. (Also, how did you make them last that long??)
  • To Freeze. Place cookies in an airtight freezer-safe container in the freezer for up to 3 months. Let thaw overnight in the refrigerator, then transfer to room temperature.

Meal Prep Tip

You can freeze monster cookie dough. Portion the dough into cookie dough balls and arrange them on a parchment-lined baking sheet. Place the sheet in the freezer until the dough is firm, then transfer to an airtight freezer-safe storage container and freeze for up to 3 months. Bake directly from frozen, adding to the baking time as needed. You’ll love yourself for having these on hand.

a fudgy monster cookie on a plate with m&ms

What to Serve with Monster Cookies

Frequently Asked Questions

Can I Swap Quick Oats for Rolled Oats?

While I prefer using rolled, old fashioned oats, you could use quick oats for this recipe. The oat pieces won’t be as prominent, but the cookies will still be delicious.

What Other Mix-Ins Can I Add?

If you’d like to add some additional mix-ins to your soft monster cookies (or don’t have some on hand), you could try white chocolate chips, pretzels, chopped nuts, granola (like my Granola Cookies), or shredded coconut.

Are Monster Cookies Healthy?

While I’ve used a few healthy swaps in this recipe, they are not what I’d consider a “healthy” food. If you’re looking for a more wholesome cookie recipe, I’d suggest trying my Healthy Peanut Butter Cookie, Healthy Oatmeal Cookies, or these Peanut Butter Protein Cookies.

Monster Cookies

5 from 20 votes
The BEST monster cookies recipe ever! Soft, chewy, and PACKED with peanut butter, chocolate, oats, and M&Ms. Easy, perfect, and classic!

Prep: 20 minutes
Cook: 10 minutes
Total: 30 minutes

Servings: 36 -40 small (2-inch) cookies



  • In a large mixing bowl, cream butter, brown sugar, and granulated sugar until light and fluffy, about 3 minutes.
  • Add peanut butter and beat until fluffy again, about 2 minutes, scraping down the bowl as needed. Beat in egg and vanilla until combined.
  • Sprinkle the baking soda and salt over the top. With the mixer on low, gradually add the flour, mixing just until the flour disappears.
  • Slowly beat in the oats. By hand, stir in the M&Ms, chocolate chips, and peanut butter chips. If time allows, chill dough for 30 minutes or overnight.
  • When ready to bake, place racks in the upper and lower thirds of the oven and preheat the oven to 350°F. Line two cookie sheets with parchment paper or a silicone baking mat. Drop cookies onto the sheets by rounded tablespoons. Bake for 10 minutes in the upper and lower thirds of the oven, until lightly golden brown (cookies may appear underdone).
  • Let rest on cookie sheet for 5 minutes, then transfer to a wire rack to cool. Serve with a big glass of cold milk.



  • TO STORE: Store cookies in an airtight container for up to 1 week or freeze for up to 3 months. Let thaw overnight in the refrigerator, then transfer to the counter.
  • TO FREEZE: Portion the dough into balls and arrange on a parchment-lined baking sheet. Place the sheet in the freezer until the dough is firm, then transfer to an airtight container or freezer-grade ziptop bag and freeze for up to 3 months. Bake directly from frozen, adding to the baking time as needed.


Serving: 1(of 36) cookiesCalories: 126kcalCarbohydrates: 14gProtein: 2gFat: 8gSaturated Fat: 4gCholesterol: 12mgFiber: 1gSugar: 10g

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Erin Clarke

Hi, I'm Erin Clarke, and I'm fearlessly dedicated to making healthy food that's affordable, easy-to-make, and best of all DELISH. I'm the author and recipe developer here at and of The Well Plated Cookbook. I adore both sweets and veggies, and I am on a mission to save you time and dishes. WELCOME!

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  1. I have never made monster cookies but they always look so incredible! I am pinning this recipe for sure!

  2. haha my sister and I did the exact same thing as kids. She liked nerds and sour patch kids and I was always about the chocolate/peanut butter combo. And we also clearly blasted halloween music while doing this – monster mash anyone??

    I love these cookies – I haven’t made monster cookies in far far too long.

  3. Me amnd my mom have said many times that monster cookies truly are the best cookies. Ever. I think it is the oats and MnMs. I’ve never made them with pb chips and will definitely throw those in next time. So true about single serving … haha, there is no such thing!

  4. Well, you had me at chocolate and peanut butter! These look amazing, and since I haven’t made monster cookies in ages, they are totally going on the “to-make” list.

    1. Rachel, I hadn’t baked monster cookies in forever, and they totally hit the spot. I hope they do for you too!

  5. Okay, I have a confession… I never really jumped on the M&M’s-in-a-cookie band wagon… but I think that is all about to change. I was all about the peanut butter and chocolate as a kid, too (and still am!), and these cookies sound over-the-top in the best possible way. And they are so cute and tiny! I would eat a dozen without thinking twice. Nom!

  6. I love how fun these look and I’m definitely a sucker for the pb + chocolate + oats combo, but it’s super dangerous for me to have m&m’s around, because I always eat them all before putting them in the cookies oooOOooops. They’re so yummy, it’s impossible to stop at one ;)

    1. I must confess…while I had half a bag of M&Ms leftover after baking these, that stash didn’t last long. They are just so easy to snitch!

  7. I love a good monster cookie! I was, and still am, only in the Halloween spirit for the pb & chocolate candy (Reese’s were like hitting the jackpot, let’s face it), but now that I am old enough to buy my own and bake them into cookies, that Halloween happiness can last year round.

    1. Reeses = MONEY! And it’s true, we can buy candy all year, but Halloween seems like such a fun excuse. Power of being a grown up!

  8. I am not too crazy about sweet and sour variety either. If we were sisters, it would not have ended well :P

    1. An epic battle for the ages! We’d have to do twice the trick or treating, just to make sure we both walked away with a satisfactory stash :)

  9. These look awesome! Monster cookies are one of my favorites. In my experience they’re really good for shipping during the holiday season too since they are sturdy and stay nice and chewy for a few days!

  10. I love monster cookies! I actually can’t believe I don’t even have a recipe on my blog for it. They’re definitely one of my absolute favorite cookies that remind me of childhood! I remember they were all I wanted to make. Yours looks fabulous!

  11. Halloween is made for monster cookies! I like to throw every candy I can into this dough and call it supper.

  12. I LOVE monster cookies! They are so easy, fun and adaptable. These are perfect for Halloween!!!

  13. What a great way to use up Halloween candy! Plus I’m a sucker for anything with peanut butter chips – I love those little things! These look so good

      1. Oh and I had pinned them earlier and then I went to FG and they’re front and center – these babies are the hot ticket today :)

        1. WHOO HOO! I didn’t even know they’d been published on FG yet, so this totally makes my day! Thanks so much for telling me Averie (and for pinning them too). You are simply the best :-D

  14. They look oh so good. I’m sure my kids would love me forever if I made them these. Well, maybe not forever but at least the rest of the day. ;)

    1. Melanie, I think your kids would love these! Mostly because my husband does and he’s a kid at heart ;-) Thanks so much and hope you all enjoy!

  15. Monster Cookies are one of my all-time favorite desserts! I’ve never made them with peanut butter chips so I can’t wait to try your version!

    1. If you love peanut butter, you will love the PB chip addition Kelly. It gives the cookies an extra PB boost that I find totally irresistable!

  16. Oh. My. Yum! These cookies look delicious! Fingers crossed the trick-or-treaters leave me enough M&M’s so I can make these this weekend.

    And thanks for commenting on my blog. Now I’ve found yours and I love it! Adding you to my reader. Can’t wait to see what you make next : )

    1. You are such a doll, and I’m so glad I found your blog too! Thanks a million Natalie!
      RE: M&M leftovers <---hide 'em at the bottom of the bowl ;-)

      1. Now THAT is a good idea. Might hide a little of all the candy while I’m at it, don’t tell anyone ; )

    1. Thanks Jessica!!!! I was obviously way excited about them, lol. If you give them a try, I’d love to hear what you think! If they are your fave, you’ll be a great judge :)

  17. Oh my goodness, look at these gorgeous little colorful gems! You’ve totally taken me back with these cookies, Erin. They’re dangerously easy, so I’ve gotta give them a go!

  18. These monster cookies look perfect, I love how fun they are. Definitely on the list of sweets to make!

  19. I NEVER make cookies but I think I’ll have to try these. I adore PB&C.

    Would it be inappropriate to steal my kid’s Halloween candy to make these? Or worse, hypocritical if I were to forbid candy but let him eat candy in a cookie? Ah, the great dilemmas in parenting…

    1. Sarah, if you adore PB&C, these cookies have your name written all over them! Mega parental conflict. I think if you steal the candy, give your kiddos a cookie or two, then hide the rest for your personal midnight snack needs, everyone will walk away happy ;-)

  20. Ohhh how I wish I could go trick-or-treating tomorrow just to get candy for these cookies!! Guess I’ll be one of the crazies raiding the discounted Halloween candy!

    1. Taylor, I am forever “one of the crazies” going after the clearance candy. Who doesn’t love a bargain?? Go for it girl!

  21. Hi Erin! These cookies are loaded with all sorts of goodness! I would have a hard time not eating the entire batch! Thank you for sharing them with us!

    1. Thanks so much Monet! And since these cookies are in honor of Halloween, I’d say eating the whole batch is complete acceptable ;-)

  22. I have such great memories of candy sorting and swapping- maybe the best part of Halloween! These cookies look like perfection :-)

    1. I think the candy swap is a key part of childhood Rachel! Maybe that’s where we first learn negotiation skills? :)

  23. I’ve never heard of a monster cookie. Clearly, I had a huge deficit in my early development (I need to remedy that now by eating as many of these cookies as possible, just so… well, I get a good idea as to how wonderful they are). One problem: peanut butter chips don’t exist in Australia *waaaah!*. Should I just omit them altogether or should I add something else? xx

    1. Peanut butter chip tragedy! You need to come to the states and stock up ASAP Laura ;-) Feel free to swap out the PB chips for whatever mix ins you like: more chocolate chips, butterscotch chips, chopped candy bars, or if you want to add more PB flavor, chopped peanuts would be delicious too. That’s the beauty of monster cookies: they transform to fit your pantry!

  24. These sound so good! Just wondered – can I use all purpose flour instead of whole wheat? It’s all I have at home right now. Thank you!

  25. Thank you, Erin, for the you tube. That was very helpful! I’ve made monster cookies before but found new tips I am eager to apply, like place in the fridge those 30 mins. before baking. I also appreciate the way you give explanations, ex., using dark brown sugar. I have never used that. Needless to say, I am eager to try Monster Cookies in the near future!! Very near! :)

  26. Monster cookies are my ALL TIME favorite cookie!! I loved coming up with a healthier version too :)

  27. Oh my word!!! I can not stop eating these….so yummy!!! 
    I do have to admit I only had dark choc chips to put in them so I’m sure they’re not as good as they could be. It’s a perfect ratio of peanut butter, oats & chocolate! Thanks for another fab recipe!! 5 stars

    1. Lela, I’m sure dark chocolate chips are delicious too! I’m so glad to hear you enjoy the cookies.

  28. Keeper!  These are so so good.   I ate five after baking the first batch, could not help myself (I used a small cookie scoop lol).  I did not have peanut butter chips so I substituted butter scotch chips.  I will make these again and again.  I will buy M&Ms just to make these.5 stars

  29. eek! my comment disappeared! it SHOULD have said this:
    LOVE these, the recipe is awesome, no substitutes or adjustments needed and, I have to say, it’s a relief that this recipe is scaled down in servings from back in the day (70’s) when we made enough for an army and us kids would gather around the BIG mixing bowl and all 4 of us would mix the final ingredients by hand all at once. :) Thank you!5 stars

  30. In a blizzard it’s fun to bake. It was between this or Paula Dean’s recipe. This one was my choice, so glad I did. These are very easy and super delicious!!! Thanks for sharing ;)5 stars

    1. YAY! I’m so happy to hear that you enjoyed this recipe, Norma! Thank you for taking the time to share this kind review!

  31. For those with peanut allergies and with “no nut” warnings in schools,  what do you suggest using in place of the peanut butter?  Thank you. 

    1. Hi Cynthia! You could try using sunflower butter, but it may turn them a greenish color. Any other type of nut butter would work as well. I hope this helps!

    1. Hi Tania! I have not tried this swap before, so unfortunately, I can’t vouch for the results. If you decide to experiment, I’d love to hear how it goes!

  32. I was expecting to like these, but what I didn’t know was how much I’d LOVE these!! Easy to make, tasty, perfect texture, delicious all around! The only issue is trying not to eat them all at once :)5 stars

  33. During this q, I have been baking different cookies about every week, for my children, their wives and grandchildren and our household of two. A dozen people total. Requests for family recipes & exploring new options has been deliciously fun! MONSTER COOKIES were a great choice for the kid in all of us! Colorful with M&Ms, peanut butter & dark chocolate chips! EVERYTHING to love and devour ❤️ There are already requests for a repeat of them! “Q Delivery Service” is eagerly anticipated & thriving ???5 stars

  34. These are absolutely the BEST cookies! I didn’t have the candies or peanut butter chips on hand, so I suppose I didn’t actually make “Monster” cookies. I used about a cup of chocolate chunks for the add ins and chunky peanut butter instead of creamy, but otherwise followed the recipe. They are the perfect texture, perfect taste, and I can’t get enough of them. This will now be my go to cookie recipe. 5 stars

  35. I made these for Christmas this year and turned out delicious. My kids and my wife loved them. Definitely will be making these a lot more often.5 stars

  36. Delicious! These were super popular back in the 1970s when I was a young elementary teacher. Kids loved them!5 stars

  37. My 6 year old and I turned these into a Valentine’s Day recipe by using pink, red and white M&Ms. They turned out delish!!!!! So cute and chewy and flavorful! We did add an extra egg at the end right before the chips & M&Ms to soften the dough a bit so it would be easier to fold in the mixins.5 stars

  38. These are the BEST monster cookies I have ever made! They are crunchy and soft at the same time and have the perfect amount of peanut butter.

    I will be making these for years to come!

  39. Great cookie for tomorrow’s track meet at Bosque School! As per your comment under your Healthy Oatmeal Cookie recipe, I “healthified” these a bit by using raisins, nuts, and dark chocolate chips as the mix-ins. Used whole-wheat pastry flour, which I’ve always thought is great. Oh and cut the sugar by 1/3. But definitely used ALL the butter! Thanks so much for the recipe!5 stars

  40. Fabulous! Made these for a friend, she went “ Gaga “😂. On that note, making her a batch today, plus a batch for her freezer. Thank You so much for sharing!5 stars

  41. It’s a gloomy, cold & rainy day here, so what better way to brighten things up than with cookies! We are big fans of monster cookies, so I was excited to try this recipe. Absolutely delicious! You’d never know they were made with white whole wheat flour. Definitely a 5 star recipe! Yummy!5 stars