Monster cookie bars couldn’t be easier to make. This sweet treat is a great way to use up leftover candy and bakes up in no time to make your littlest monsters happy!
Preheat oven to 350°F. Line a 9x13 inch baking pan with foil, leaving about 1 inch of the foil extending over the edges of the pan. The extra foil will create handles that you can use to lift the Monster Cookie Bars from the pan. Spray foil with nonstick cooking spray. Set pan aside.
In the bowl of a stand mixer fitted with the paddle attachment, or in a large bowl with an electric mixer, cream butter, peanut butter and sugars on medium speed for about 3 minutes. Add in vanilla and eggs and mix until combined.
In a medium bowl, whisk together the flour, baking soda, salt and oats. Gradually add the dry ingredients into the butter mixture until thoroughly incorporated. Stir in chocolate chips and add-ins.
Spoon batter into prepared pan and spread into an even layer. If desired, top batter with additional chocolate chips, M&M’s or other add-ins, pressing them lightly into the batter. Bake in preheated oven for 30-35 minutes. If desired, sprinkle bars with flaky sea salt after removing from oven. Place pan on a cooling rack and cool completely before cutting into squares.
Notes
Monster Cookie Bars can be stored in an airtight container at room temperature for up to 3 days.I sometimes like to use Hoody’s Peanut Butter Chocolate Mix from Costco in these bars since it has all of the mix-ins we love. Helpful resources: