Monster Cookie Bars

5 from 12 votes

Monster Cookie Bars are the ultimate cookie mashup because they are chock full of oatmeal, peanut butter, M&Ms, and chocolate chips! Soft and chewy cookies in a one-bowl recipe.

Prep Time15

Cook Time20

Total Time35

Course: Dessert

Cuisine: American

Servings: 2x2 squares

Calories: 333kcal

Author: Rachel

Ingredients

Oatmeal Cookie Bars

½ cup Unsalted Butter softened
1 cup Light Brown Sugar
1 teaspoon Vanilla Extract
2 Eggs
2 cup All-Purpose Flour
2 cup Old-fashioned Oats
½ cup Peanut Butter Creamy or Crunchy
1 teaspoon Baking Soda
½ teaspoon Salt
1 cup Chocolate Chips about 6 ounces
1 cup M&Ms

Instructions

Preheat oven to 350 degrees F. Grease a 9x13 deep pan and set aside.
In a large mixing bowl, combine ½ cup Unsalted Butter, 1 cup Light Brown Sugar and 1 teaspoon Vanilla Extract until smooth. Break 2 Eggs and beat until smooth. Add in 2 cup All-Purpose Flour, 2 cup Old-fashioned Oats, ½ cup Peanut Butter, 1 teaspoon Baking Soda, and ½ teaspoon Salt. You can use a stand mixer or electric mixer or hand mix.
Using a large spoon, stir in 1 cup Chocolate Chips and half of 1 cup M&Ms to the batter.
Press batter into greased baking dish. Sprinkle remaining M&Ms on the top, pressing them into the dough slightly.
Bake for 15-18 minutes or until the edges crisp and slightly brown or a toothpick comes out clean. Let cool a bit before slicing. Letting them cool completely is best, but who could wait that long!

Notes

Store: These can be stored in an air-tight container at room temperate for 3-4 days.

Freeze: You may freeze these bars to enjoy for later and they should last about 2 months. I recommend cutting and wrapping the bars individually to prevent sticking.

Make ahead dough: The dough can be prepared and stored in the refrigerator up to 48 hours ahead of time. It also freezes well. Make sure it is in an air-tight container and brought to room temperature on the counter before baking.

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