Monster Cookie Bars

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4.5 from 2 reviews

These monster cookie bars are soft and chewy, loaded with chocolate chips, candy morsels, and peanut butter flavor!


  • ½ cup (113 gm) unsalted butter, at room temperature
  • ½ cup (140 gm) creamy peanut butter (not natural)
  • ½ cup (100 gm) light brown sugar, packed 
  • ¼ cup (50 gm) granulated sugar
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 1 cup (140 gm) all-purpose flour
  • 1 cup (90 gm) rolled oats
  • 1 teaspoon baking powder
  • ½ teaspoon salt
  • ¾ cups semisweet chocolate chips
  • ½ cup M&Ms or candy-coated chocolates


  1. Preheat the oven to 350 degrees Fahrenheit. Line an 8” pan with aluminum foil, allowing the ends to extend beyond the sides of the pan. Lightly grease with cooking spray and set aside. 
  2. In a large bowl or the bowl of a stand mixer, cream the butter and peanut butter until combined. Add the brown sugar and granulated sugar and stir until smooth. Scrape the sides of the bowl and add the eggs and vanilla extracts, stirring until combined. Scrape the sides of the bowl again and add in the flour, oats, baking powder, and salt. Stir on low until barely combined. Add in the chocolate chips and chocolate candies and stir until combined. Use a rubber spatula to smooth the dough into the bottom of the prepared pan. Bake in the preheated oven for about 25-30 minutes or until the edges and center of your bars are golden and no longer jiggly. Allow to cool completely prior to removing from pan and cutting. Enjoy!