Line an 8x8 baking pan with aluminum foil or parchment paper, leaving a few inches of overhang on two of the sides like handles. Generously coat the foil or paper with baking spray. Set aside.
In a microwave-safe bowl or a small saucepan over medium heat, combine the honey, peanut butter, and coconut oil. Melt gently and stir until smooth and combined. Remove from the heat and stir in the vanilla extract. Let cool for 5 minutes.
In a large mixing bowl, combine the oats, cereal, flaxseed, cinnamon, and salt, then stir in the dried fruit, nuts/seeds, and chocolate chips.
Pour the peanut butter mixture over the top, then stir until the ingredients are evenly moistened.
Scoop the mixture into the prepared baking pan, then with a spatula or your fingers, press into an even layer. If the mixture is too sticky, lay a sheet of plastic wrap over the top, then press on its surface.
Place the bars in the refrigerator to set, at least 2 hours or overnight.
Once fully chilled, remove the bars from the pan with the foil or paper “handles,” then, using a very sharp knife, slice into bars. Enjoy immediately or store in the refrigerator or freezer for later.
NOTE ON PEANUT BUTTER: I used Jif Creamy Natural Peanut Butter, which does not need to be stirred at room temperature. If you use a different brand or formula, you may need to alter the amount of liquid/oats/salt to suit your tastes and ensure the bars hold together once chilled. This recipe is flexible and forgiving, so feel free to adjust as needed.
TO STORE: Store leftovers in the refrigerator for 2 to 3 weeks in a covered container.
TO FREEZE: Trail mix chewy granola bars may be frozen for up to 3 months when wrapped tightly in plastic and stored in a freezer-safe container.