Marshmallow Crunch Brownie Bars - A stack of brownies with a layer of marshmallows and crisp chocolate and peanut butter topping.

Marshmallow Crunch Brownie Bars

Super fudgy brownies topped with a layer of marshmallows and a chocolate, peanut butter and Rice Krispies mixture.
Course Snack
Cuisine American
Prep 30 minutes
Cook 30 minutes
Total 1 hour
Servings 24 bars
Calories 340 kcal
Author Michelle


For the Brownie Base

  • 4 ounces unsweetened chocolate
  • cup unsalted butter
  • cups semisweet chocolate chips, divided
  • 1⅓ cups all-purpose flour
  • 1 teaspoon baking powder
  • ½ teaspoon salt
  • 4 eggs at room temperature
  • 2 cups granulated sugar
  • 2 teaspoons vanilla extract

For the Marshmallow Layer

  • 10.5 ounce bag miniature marshmallows

For the Crispy Chocolate Peanut Butter Layer

  • cups milk 255 grams chocolate chips
  • 1 cup smooth peanut butter
  • 1 tablespoon unsalted butter
  • cups Rice Krispies cereal
US Customary - Metric


  1. Make the Brownies: Preheat the oven to 350 degrees F. Grease a 9x13-inch pan.
  2. In a medium saucepan, melt the unsweetened chocolate, butter and ¾ cup of the semisweet chocolate chips over medium heat. Stir occasionally while melting. Set aside and cool for 5 minutes.
  3. In a large bowl, whisk the eggs thoroughly. Add the sugar and vanilla, and whisk until well blended. Stir the melted ingredients into the egg mixture, mixing well. Sift the flour, baking powder and salt into the mixture and stir well. Fold in the remaining ½ cup semisweet chocolate chips.
  4. Pour the batter into the prepared pan, smoothing it into an even layer. Bake for 25 to 30 minutes, or until a toothpick inserted into the corner of of the pan comes out with moist crumbs.
  5. Remove the brownies from the oven and immediately sprinkle the marshmallows over them. Return the pan to the oven for 3 more minutes.
  6. Make the Crispy Chocolate Peanut Butter Layer: Meanwhile, place the milk chocolate chips, peanut butter, and tablespoon of butter in a medium saucepan. Melt over low heat, stirring constantly, until completely melted. Remove from heat, add the Rice Krispies and mix well. Allow to cool for 3 minutes.
  7. Spread the mixture evenly over the marshmallow layer. Allow to cool to room temperature, then refrigerate for 30 minutes to make it easier to slice. The brownies can be stored at room temperature or in the refrigerator for up to 1 week.

Recipe Notes

Nutritional values are based on one serving

Nutrition Facts
Marshmallow Crunch Brownie Bars
Amount Per Serving
Calories 340 Calories from Fat 144
% Daily Value*
Total Fat 16g 25%
Saturated Fat 8g 40%
Cholesterol 44mg 15%
Sodium 145mg 6%
Potassium 222mg 6%
Total Carbohydrates 44g 15%
Dietary Fiber 2g 8%
Sugars 29g
Protein 6g 12%
Vitamin A 7.2%
Vitamin C 1.3%
Calcium 4.5%
Iron 14.7%
* Percent Daily Values are based on a 2000 calorie diet.