Monster Cookies are soft and filled with peanut butter, oats, chocolate chips, and M&Ms. After searching for the best Monster Cookies recipe and not finding one, I came up with these easy chewy monster cookies my own! These are perfect!
Preheat oven to 350 degrees and line a cookie sheet with parchment paper.
In a medium bowl, whisk together the flour, baking soda, and salt.
In a large bowl of a stand mixer or with a hand mixer, cream together the butter, brown sugar, white sugar, and peanut butter.
Add the egg, egg yolk, and vanilla and mix well until creamy scraping down the sides of the bowl.
Slowly add the flour mixture until incorporated. Mix in the oats.
Stir in the peanut butter chips, chocolate chips, and M&Ms. You can use a mixer (if you're lazy like me) or stir in by hand. Stirring in by hand makes sure that the M&Ms don't break.
Place cookie dough balls, around 1 1/2 Tablespoons dough each, on the parchment sheet. You can hand place extra M&Ms on top, pressing slightly in, to give the cookies a professional look.
Bake for 9-11 minutes. Make sure not to overbake. The cookies will not be brown and will continue to cook as they cool on the pan.
Store in an airtight container. Makes around 2 1/2 dozen.