If you’re not familiar with them, the cookies are traditionally made with a peanut butter dough and then loaded up with oats, chocolate chips and M&M candies. While I love cookies, sometimes bars get overlooked, so this weekend I baked up a whole pan of monster cookie bars! They were a big hit on Halloween while we were waiting to get Joseph into his costume, and still popular after Sunday dinner yesterday.
There are a million and one recipes floating around the internet for monster cookies and I’ve tried a few different versions, but this one is my most recent favorite.
The dough is soft, the peanut butter flavor comes through but isn’t overpowering, the oats are abundant, and there is a ton of chocolate thanks to the chips and M&M’s. You could totally play around with this recipe and switch up the add-ins, but I love the classic combination of chocolate chips and M&M’s – you just can’t go wrong!
I think it goes without saying that these would be super popular with kids, but I can vouch for the fact that they’re incredibly popular with adults, too!
Preheat the oven to 350 degrees F. Grease a 9x13-inch paking pan and line with parchment paper so that it hangs over two sides.
In a small bowl, whisk together the flour, baking soda, cornstarch, baking powder and salt.
In a large bowl, cream together the butter, brown sugar, and peanut butter on medium speed until light and fluffy, about 3 minutes. Add the egg and vanilla, scraping down the sides of the bowl as needed. Reduce the mixer speed to low and slowly add the flour mixture to the wet ingredients and mix until just combined. Using a rubber spatula, stir in the oats, chocolate chips and M&M's by hand.
Turn the dough out into the prepared baking sheet and press/spread into an even layer. Press additional M&M's onto the top of the dough. Bake for 15 to 17 minutes, until the edges are set and lightly browned and the top still looks slightly undercooked. Remove from the oven and cool completely before cutting into bars. The bars should be stored in an airtight container at room temperature for up to 4 days.