Marshmallow Crunch Brownie Bars

Super fudgy brownies topped with a layer of marshmallows and a chocolate, peanut butter and Rice Krispies mixture.

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

Imagine this: rich, decadent brownies. Topped with ooey, gooey marshmallows. Topped again with chocolate-peanut butter-Rice Krispy deliciousness.

If you love fudgy brownies and can’t resist crazy brownie concoctions, you are absolutely, positively going to love these brownie bars. Part brownie, part s’more, and part Rice Krispy treat. It’s everything you know and love, baked up into one amazing dessert.

These were my go-to party dessert for ages (I eventually made a peanut butter cup version!), and I recently revived the recipe, much to the delight of everyone in my family.

MY OTHER RECIPES


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

I’m fairly certain that I don’t need to convince anyone here that these brownies are the ultimate in fabulous ideas. A couple of notes for you since I made these originally…

  • I am keeping the brownie recipe the same below in case anyone wants to keep using the original recipe, but I totally recommend using my better-than-box-mix brownies as the base recipe. It’s my go-to brownie recipe and I think it’s the best first layer when making crazy brownie concoctions.
  • We had to go peanut-free in our house since finding out about Joseph’s allergy, and I have successfully made these with Sunbutter in the top layer. It tastes delicious and I had no issues with it setting up. (I used the Sunbutter Natural version with the yellow lid; I can’t speak to the other varieties).

Now, you’ll want to hurry up and make these immediately. All of your family and friends will love you forever.

Marshmallow Crunch Brownie Bars - Take a big bite of these fudgy brownies topped with marshmallows and a chocolate/peanut butter/Rice Krispies mixture.

Four years ago: Fresh Peach Ice Cream
Five years ago: Homemade Pineapple Ice Cream Topping

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Marshmallow Crunch Brownie Bars

Super fudgy brownies topped with a layer of marshmallows and a chocolate, peanut butter and Rice Krispies mixture.

Ingredients:

For the Brownie Base

  • 4 ounces unsweetened chocolate
  • ⅔ cup (151 grams) unsalted butter
  • 1¼ cups (213 grams) semisweet chocolate chips, divided
  • 1⅓ cups (189 grams) all-purpose flour
  • 1 teaspoon baking powder
  • ½ teaspoon salt
  • 4 eggs, at room temperature
  • 2 cups (397 grams) granulated sugar
  • 2 teaspoons vanilla extract

For the Marshmallow Layer

  • 1 (10.5-ounce) bag miniature marshmallows

For the Crispy Chocolate Peanut Butter Layer

  • 1½ cups milk (255 grams) chocolate chips
  • 1 cup (270 grams) smooth peanut butter
  • 1 tablespoon unsalted butter
  • 1½ cups (42 grams) Rice Krispies cereal

Directions:

  1. Make the Brownies: Preheat the oven to 350 degrees F. Grease a 9×13-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:

  • Do not use natural peanut butter, as it is too oily.
  • I have made this successfully with Sunbutter (the natural version, with yellow lid) in place of the peanut butter with no issues.
  • Since originally making this recipe, my better-than-box-mix brownies have become my go-to recipe for brownie creations, so I recommend using that one as the base!

Did you make this recipe?

Leave a review below, then snap a picture and tag @thebrowneyedbaker on Instagram so I can see it!

(Adapted from Culinary Concoctions by Peabody; originally from Buttercup Bakes at Home by Jennifer Appel)

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Marshmallow Crunch Brownie Bars - Super fudgy brownies topped with marshmallows and a chocolate/peanut butter/Rice Krispies mixture. A crowd favorite!

This recipe was originally published on October 5, 2009.

Marshmallow Crunch Brownie Bars - Super fudgy brownies topped with a marshmallow layer and a chocolate, peanut butter and Rice Krispies mixture. A huge crowd favorite!