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Stack of M&M Cookie Bars

M&M Cookie Bars

These soft and chewy cookie bars are filled with chocolate chips and colorful M&M's. This recipe is even easier than making cookies!
Course Dessert
Cuisine American
Prep Time 10 minutes
Cook Time 25 minutes
Total Time 35 minutes
Servings 9
Calories 306kcal


  • ½ cup unsalted butter, melted and still a little warm
  • ½ cup firmly packed brown sugar*
  • ¼ cup granulated sugar
  • 1 large egg
  • 1 teaspoon pure vanilla extract
  • 1 cup all purpose flour
  • ¾ teaspoon baking powder
  • ¼ teaspoon salt
  • 1 teaspoon cornstarch
  • ¾ cup combination of chocolate chips and mini M&M's plus a few more for topping


  • Preheat oven to 350°F with a rack in the center of the oven.
  • Add the warm butter to a large bowl along with both sugars. Whisk until fully combined (at least 1 minute). Add eggs and vanilla and whisk until combined. Tap the whisk on the side of the bowl, allowing all the excess batter to run into the bowl. Remove the whisk.
  • Sprinkle the flour, baking powder, salt, and cornstarch over the top of the sugar mixture. Use a rubber spatula or wooden spoon to stir until well combined. The dough will be fairly "wet" - thinner than cookie dough but thicker than brownie batter. Add the chocolate chips and M&M's and stir until combined.
  • Grease an 8x8 baking dish. Optional: line the pan with foil and grease the foil (this makes for easy removal). Scoop the dough into the prepared pan and spread it into an even layer. If desired you can add a few extra chocolate chips and M&M's on top. Bake for 22-26 minutes, until the center is set (not jiggly) and the bars are turning golden brown. Be careful not to overbake.
  • Place the pan on a cooling rack and cool completely before slicing. The bars will hold together best once completely cool. If you want to eat them when they are warm and gooey I recommend using a fork.


*Brown sugar: You can use light or dark brown sugar. Dark brown sugar will make the bars more moist and gooey.


Calories: 306kcal | Carbohydrates: 36g | Protein: 3g | Fat: 17g | Saturated Fat: 10g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 5g | Trans Fat: 0.4g | Cholesterol: 49mg | Sodium: 79mg | Potassium: 161mg | Fiber: 2g | Sugar: 23g | Vitamin A: 353IU | Calcium: 42mg | Iron: 2mg