Yesterday, I realized that I have been baking these Monster Cookies for 10 years, which made me feel…old. BUT not old enough to skip silently evaluating every single cookie and carefully selecting the one with the most chocolate. 

BEST Monster Cookies recipe. Thick, soft, and chewy peanut butter oatmeal cookies, stuffed with chocolate chips, M&M candies, and peanut butter chips. Our favorite cookie recipe!

Considering I grew up with flour on my shirt and chocolate on my face, I am sure I have many recipes in my life that I’ve been baking for longer than 10 years, but I remember the first time I tasted these Monster Cookies especially vividly.

I was introduced to these thick, chewy Monster Cookies by my first ever “work friend” (a.k.a. real friend who happened to have a cubical in my vicinity), Lindsey.

Lindsey brought a batch of the most perfect Monster Cookies in creation to the office and, as soon as I could come up for air after devouring what I told myself was three Monster Cookies but what was mathematically closer to five, I asked her for the recipe. She told me it was her mom’s and she’d get it to me soon.

I’m not sure how far back the recipe lineage continues (Lindsey got the recipe from her mom, who got it from her mom, etc.), but I would not be surprised if these easy Monster Cookies dated back to the invention of chocolate and peanut butter. They are perfect in that special way that tastes of the fine tuning of generations.

Thick, soft, chewy Monster Cookies recipe

I originally shared this Monster Cookies recipe five years ago. Today, I’m giving it a facelift with fresh photos and a new video, because these Monster Cookies are every bit as fabulous as I am making them out to be.

They’re supremely ooey-gooey, thick and chewy, and jam-packed with bits and bites of chocolate and peanut butter in various forms (chips, candies, and straight-up PB). They deserve all of the dramatic statements you care to throw their way.

I’ll start.

Best Monster Cookies EVER.

^^Said it. Standing by it.

Easy Monster Cookies with oatmeal, peanut butter, and M&M candies. Better than Pioneer Woman!

Lindsey mom’s original name for this recipe is “nutritious cookies” because of redeeming ingredients like peanut butter and oatmeal. The original recipe does not include M&Ms, but I’ve taken to adding them for color and crunch…and because it’s hard to imagine a good reason not to include more chocolate.

Now, I can’t in good faith type that these Monster Cookies are *quite* as nutritious as say, this giant Healthy Peanut Butter Cookie or these Peanut Butter Protein Cookies.

I have, however, made a few tweaks over time to put the recipe above the nutritional profile of Monster Cookies Pioneer Woman or Monster Cookies Paula-style, such as using whole wheat flour.

Easy Monster Cookies. Soft, chewy, and perfect every time!

I prefer baking my Monster Cookies bite-sized (then, ahem, eating more), but if you prefer giant Monster Cookies, you can certainly scoop the dough larger and extend the bake time by a few minutes.

As far as mix-ins go, Monster Cookies traditionally call for chocolate chips and M&M candies, but I follow Lindsey and her mom’s move of adding peanut butter chips to the mix too. The double hit of PB is the secret to making these the best, most addictive Monster Cookies you’ll try.

Recommended Tools to Bake this Monster Cookies Recipe

Monster Cookies

The BEST Monster Cookies recipe ever! Thick, soft, chewy and PACKED with chocolate chips, peanut butter chips, and M&M candies. Easy and perfect!

  • 1/2 cup (1 stick) unsalted butter, softened
  • 3/4 cup firmly packed dark brown sugar
  • 1/4 cup granulated sugar
  • 1/2 cup creamy peanut butter
  • 1 large egg (at room temperature)
  • 1 teaspoon pure vanilla extract
  • 1/2 teaspoon baking soda
  • 1/4 teaspoon kosher salt
  • 1 cup  white whole wheat flour ( or whole wheat pastry flour)
  • 1 cup old fashioned rolled oats
  • 3/4 cup dark chocolate M&Ms
  • 1/2 cup semi-sweet or dark chocolate chips
  • 1/2 cup peanut butter chips
  1. 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.
  2. 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.
  3. When ready to bake, place racks in the upper and lower thirds of the oven and preheat the oven to 350 degrees 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.
  • Store leftover Monster 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 unbaked cookies: 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.