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Monster cookie bars are a fun treat loaded with peanut butter, oats, chocolate chips, peanut butter chips, and mini m&m's. They bake up perfectly soft, chewy, and thick. A fun treat to make with the kids or great for back-to-school lunches or after school treat. 

Soft-Baked Monster Cookie Bars

Monster cookie bars are a fun treat loaded with peanut butter, oats, chocolate chips, peanut butter chips, and mini m&m's. They bake up perfectly soft, chewy, and thick. A fun treat to make with the kids or great for back-to-school lunches or after school treat. 

Course Dessert
Cuisine American
Keyword bars, dessert, monster cookies
Prep Time 10 minutes
Cook Time 15 minutes
Total Time 25 minutes
Servings 16
Author Jessica - Together as Family

Ingredients

  • 1 1/2 cups all-purpose flour
  • 3/4 teaspoon baking soda
  • 1/4 teaspoon salt
  • 1 cup quick oats
  • 1/2 cup (1 stick) butter, softened
  • 1/3 cup creamy peanut butter
  • 1/2 cup granulated sugar
  • 1/2 cup light brown sugar
  • 1 teaspoon vanilla extract
  • 1 large egg
  • 1 large egg yolk (discard the whites, only use the yolk)
  • 1/2 cup peanut butter chips
  • 1/2 cup mini chocolate chips
  • 1/2 cup mini m&m's

Instructions

  1. Preheat the oven to 350 degrees. Lightly grease a 9X13-inch baking pan, or line with parchment paper. Set aside.
  2. In a small bowl, whisk together the flour, baking soda, salt and oats.
  3. In a seperate large bowl, or in the bowl of a stand mixer fitted with the paddle attachment, cream together the butter, peanut butter, brown sugar, and sugar until fluffy looking and light in color, 2-3 minutes.

  4. Add in the vanilla, egg and egg yolk. Blend together well.
  5. Add the dry ingredients into the wet and mix just until combined.
  6. Add chocolate chips, peanut butter chips, m&m's and mix together just until candies are incorporated into the dough.
  7. Press the dough into the prepared pan. Bake for 15-18 minutes or until very lightly browned on the edges. The bars will still look pale and slightly underdone in the middle. That's ok. Don't over bake or the bars will be dry!

  8. Let the bars cool in the baking pan for 20-30 minutes. Cut into squares.

Recipe Notes

If wanted reserve some of the chocolate chips, peanut butter chips, and m&m's to sprinkle on top of the dough before you bake them. Be sure and gently press them down.