Monster Cookie Bars
These Monster Cookie Bars are thick, chewy, ultra ooey-gooey, and packed with peanut butter, oats, M&Ms, and three types of chocolate!
Prep Time15 mins
Cook Time30 mins
Total Time45 mins
Course: Dessert
Cuisine: American
Keyword: easy, m&ms, old fashioned oats
Servings: 24 bars
Calories: 333kcal
Author: Jennifer Debth
- 1/2 cup unsalted butter melted
- 1 cup dark brown sugar packed
- 1 cup granulated sugar
- 2 cups creamy peanut butter
- 3 large eggs
- 1 tablespoon vanilla extract
- 4 cups old fashioned oats certified gluten free if necessary
- 2 teaspoons baking soda
- 1 teaspoon salt
- 1 cup M&M’s plus more for topping
- 1 cup additional mix-ins plus more for topping (I used equal parts butterscotch chips, chocolate chunks, chocolate chips, and white chocolate chips)
Preheat oven to 350 degrees F and grease a 9x13 inch baking dish with cooking spray, then line it with a parchment paper sling.
In the bowl of your stand mixer, beat together melted butter, brown sugar, and granulated sugar until fluffy.
Beat in peanut butter, eggs, and vanilla until combined.
Add in oats, baking soda, and salt, then beat again until incorporated.
Beat in M&Ms and additional mix-ins (butterscotch chips, chocolate chunks/chips, white chocolate chips, etc.).
Pour into prepared pan, then use your hands to press the mixture into an even layer.
Press in extra toppings, if desired (this makes it look pretty).
Bake in preheated oven for 30-40 minutes or until an inserted toothpick comes out basically clean.
Cool completely before removing from the pan, slicing, and serving!
Take 5 seconds to . We greatly appreciate it!
Serving: 1bar | Calories: 333kcal | Carbohydrates: 37g | Protein: 8g | Fat: 18g | Saturated Fat: 6g | Trans Fat: 1g | Cholesterol: 35mg | Sodium: 306mg | Potassium: 211mg | Fiber: 3g | Sugar: 25g | Vitamin A: 171IU | Vitamin C: 1mg | Calcium: 39mg | Iron: 1mg