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+ servings

Monster Cookie Bars

All the flavors of the classic monster cookie - peanut butter, oatmeal, chocolate chips, M&M's,- but now in an easy-to-make bar!
Prep Time10 mins
Cook Time15 mins
Total Time35 mins
Servings: 18 bars


  • 1 stick butter unsalted, softened
  • 1 cup light brown sugar
  • 1/2 cup creamy peanut butter
  • 2 large eggs
  • 1 teaspoon pure vanilla extract
  • 1 3/4 cups all-purpose flour
  • 1 teaspoon baking soda
  • 1 teaspoon salt
  • 1 3/4 cups quick-cooking oats
  • 3/4 cup semi-sweet chocolate chips
  • 1 cup mini M&M's


  • Preheat oven to 350 degrees. Line 9x13 pan with parchment paper. Set aside.
  • Beat butter and sugar together in a large bowl of a stand mixer until creamy. Add peanut butter and vanilla and combine. Add eggs one at a time until combined.
  • In a separate medium bowl, add flour, baking soda, salt, and oats. Whisk until combined. Add dry ingredients to mixer and mix on low just until combined. Add chocolate chips and 1/4 cup of M&M's. Mix just until evenly distributed in dough.
  • Scoop dough into prepared baking pan. Using your hands, press dough firmly in pan to spread it evenly. Sprinkle remaining 1/2 cup of M&M's over dough and press them into dough.
  • Bake for 14-16 minutes, or until edges are browned and center is cooked. Remove from oven and let them cool for at least 10 minutes before cutting.


Recipe adapted from Chocolate with Grace