Thick, rich chocolate brownies topped with gooey marshmallows and smothered in creamy chocolate frosting, these fudgy Marshmallow Brownies are what sweet tooth dreams are made of. Perfect for holidays, potlucks, or just a cozy night in, they’ve got that irresistible combination of moist crumbs, melted marshmallows, and deep chocolate flavor that makes them one of my favorite brownie recipes ever.
I know some folks think brownies shouldn’t come with frosting, but I’m not one of those people. Gimme an intensely chocolatey, fudgy, rich brownie topped with gooey marshmallows and creamy chocolate frosting any day. These brownies were inspired by a favorite cookie from a sandwich shop in Utah called Cutler’s that is known for their Chocolate Marshmallow Cookies.
With a fudgy texture, puffy melted marshmallows, and a sweet chocolate frosting to seal it all in, every bite tastes like a warm summer night. Whether you’re at a backyard BBQ, birthday party, or just curled up with a glass of milk on the couch, these gooey chocolate brownies bring serious campfire vibes – no fire pit needed.
If you’re all about gooey marshmallows and rich chocolate flavor, don’t miss my recipes for S’mores Bars, S’mores Cake, Skillet S’mores Dip, and my Chocolate Peanut Butter Crunch Brownies.
Why We Love This Recipe
- I tested dozens of brownies before achieving the perfect texture and flavor that holds up to the generous layers of marshmallow and frosting on top.
- The brownie base is delicious enough to eat on its own and comes together in just one bowl to save you doing extra dishes.
- Unlike my go-to brownies recipe that I typically use, this version is made with just cocoa powder so there is no chopping of chocolate involved.
What You’ll Need
Scroll down to the recipe card below this post for ingredient quantities and full instructions.
- Evaporated Milk – Makes the frosting rich and spreadable.
- Salted Butter – Adds richness to both the brownie base and chocolate frosting. Unsalted butter works too with a pinch of extra salt.
- Granulated Sugar – Sweetens and helps create that signature crackly brownie top.
- Large Eggs – Bind the brownie batter and keep the texture moist and chewy.
- Vanilla Extract – Boosts the chocolate flavor and balances the sweetness of the marshmallows.
- All-Purpose Flour – Gives structure. Spoon and level to avoid dense brownies.
- Unsweetened Cocoa Powder – Brings bold chocolate flavor. Natural unsweetened cocoa powder works best here.
- Baking Powder – Adds a little lift so the brownies don’t bake up too heavy.
- Salt – Enhances flavor and keeps the chocolate from tasting flat.
- Mini Marshmallows – Puff into gooey clouds on top of the brownies.
- Powdered Sugar – Gives the frosting its smooth, creamy texture.
How to Make Marshmallow Brownies
- Melt butter and add sugar. In a large microwave-safe bowl, melt the salted butter until fully liquefied. Let it cool just slightly so it doesn’t scramble the eggs when they’re added in. Add the sugar on top.
- Mix until smooth. Whisk in the granulated sugar until the mixture looks thick and glossy. This step helps give that signature crackly top!
- Add eggs and vanilla. Mix in the large eggs and vanilla extract until the batter is smooth and pale yellow. It should look a bit creamy at this stage.
- Add dry ingredients. Dump in the all-purpose flour, natural unsweetened cocoa powder, baking powder, and salt. Use a rubber spatula or wooden spoon to mix the dry ingredients just until you don’t see streaks of flour. TIP: Don’t overdo it – this keeps the brownies fudgy!
- Pour into pan. Spread the brownie batter evenly into your parchment-lined or greased 9×13-inch pan. Use a spatula to level the top of the batter for even baking.
- Bake. Bake at 350°F for 25-30 minutes. It’s ready when a toothpick comes out with just a few moist crumbs.
- Add marshmallows. Scatter a full layer of miniature marshmallows over the hot brownie layer.
- Bake again. Return the pan to the oven for 3-5 minutes until the marshmallows puff up and turn gooey but not browned. We’re not going for full-melt here – just a puffy, airy, soft layer or marshmallow.
- Make the frosting. While the brownies cool a bit, combine the softened butter, cocoa powder, powdered sugar, evaporated milk, and vanilla in a large bowl. Use an electric hand mixer or stand mixer to beat the frosting until it’s light, creamy, and easily spreadable.
- Dollop frosting over marshmallows. Drop generous spoonfuls of chocolate frosting all over the top of the marshmallow layer to make it easier to spread without dragging the gooey topping around.
- Spread evenly. Use a spatula to gently smooth the frosting across the top of the marshmallows, covering every gooey peak with a thick, creamy layer of chocolate.
- Slice and serve. Once the frosting has set, cut it into squares and get ready for the compliments to roll in!
Recipe FAQ’s
Absolutely! If you’re short on time, a boxed brownie mix still gives great results – just bake as directed, then follow the steps for adding the marshmallow layer and chocolate frosting for that homemade glow-up. Try my doctored up brownie mix version for even more of a homemade taste.
These gooey marshmallow brownies will stay soft and fudgy for up to 3 days when stored in an airtight container at room temp. The marshmallow layer stays puffy and the frosting keeps that top nice and moist – just don’t let them sit uncovered, or they’ll dry out faster than you can say “extra brownie.”
Yes. Wrap individual squares tightly in plastic wrap, then place them in an airtight container or freezer-safe bag. They’ll hold up beautifully in the freezer for up to 2 months. Let frozen brownies sit at room temperature for about 30-45 minutes before digging in. You can also microwave them for a few seconds if you’re after that just-baked, gooey chocolate brownie feel – perfect for those “just one more bite” emergencies.
Tips for Success
- Line your baking dish with parchment and leave some overhang – it makes slicing and cleanup a breeze.
- Chill frosted brownies for 15 minutes and wipe the knife between cuts for neat, bakery-style squares.
- Room temperature eggs mix better and help keep the brownies extra fudgy.
- That quick second bake after adding marshmallows is key for a puffed, gooey top – don’t skip it.
- Want more chocolate flavor? Stir in some dark chocolate chips for melty, rich pockets in every bite.
Substitutions and Variations
- Swap all-purpose flour for a 1:1 gluten-free blend to make gooey chocolate brownies gluten-free without losing that fudgy texture.
- Use mini marshmallows for the classic puff, or chop large ones into small pieces for an even gooier marshmallow layer.
- Stir in a teaspoon of peppermint extract to the frosting for a minty holiday twist.
- Add chocolate chips, dark chocolate, or sweet chocolate chunks to the batter for melty pockets of extra chocolate flavor.
- Sprinkle crushed graham crackers over the marshmallow layer before frosting for a nostalgic s’mores brownie crunch.
More Fun Brownie Recipes
- Super Fudgy Homemade Brownies
- Chocolate Frosted Brownies
- M&M Brownies
- Chocolate Turtle Brownies
- Slutty Brownies
- Lemon Brownies
Marshmallow Brownies
Ingredients
Brownies
- 1 cup (227g) salted butter melted
- 2 cups (400g) granulated sugar
- 4 large eggs
- 2 teaspoons vanilla extract
- 1 cup (141g) all-purpose flour
- ⅔ cup (58g) natural unsweetened cocoa powder
- ½ teaspoon baking powder
- ½ teaspoon salt
- 1 (10-ounce) bag miniature marshmallows
Frosting
- ½ cup (113g) salted butter melted
- ¼ cup natural unsweetened cocoa powder
- 3 cups (360g) powdered sugar
- ⅓ cup evaporated milk
- 1 teaspoon vanilla extract
Instructions
- Preheat oven to 350°F. Line a 9×13-inch baking dish with a parchment paper sling or spray with baking spray.
- In a large mixing bowl, beat the butter and sugar until creamy and light. Add the eggs and vanilla extract, beating again and stopping to scrape the bottom and sides of the bowl until everything is well mixed.1 cup (227g) salted butter, 2 cups (400g) granulated sugar, 4 large eggs, 2 teaspoons vanilla extract
- Add flour, cocoa powder, baking powder, and salt. Stir just until combined, then spread into the prepared pan.1 cup (141g) all-purpose flour, ⅔ cup (58g) natural unsweetened cocoa powder, ½ teaspoon baking powder, ½ teaspoon salt
- Bake 25 to 30 minutes until a toothpick inserted into the center of the brownies comes out almost clean with just a little batter or a few crumbs on it. Remove the brownies from the oven and sprinkle with marshmallows. Return the brownies to the oven and bake for 3 to 5 minutes until marshmallows are puffy and the brownies are just done. Cool before frosting.1 (10-ounce) bag miniature marshmallows
- When the brownies have cooled, combine the butter, cocoa powder, powdered sugar, and evaporated milk in a medium mixing bowl Beat the frosting ingredients with a hand mixer until creamy and light, then spread over the cooled brownies. Cut into squares.½ cup (113g) salted butter, ¼ cup natural unsweetened cocoa powder, 3 cups (360g) powdered sugar, ⅓ cup evaporated milk, 1 teaspoon vanilla extract
Notes
Storage & Make Ahead
- Store: Keep brownies in an airtight container at room temperature for up to 3 days. If it’s warm in your kitchen, refrigerate to keep the frosting from getting too soft.
- Freeze: Wrap individual squares tightly in plastic wrap and place them in a freezer-safe container or bag. They’ll keep well for up to 2 months.
- Reheat: Let frozen brownies thaw at room temp or microwave for 10-15 seconds to bring back that warm, gooey chocolate brownie texture.
- Make Ahead: You can bake the brownie layer and add the marshmallow topping a day in advance. Frost right before serving for the best texture and flavor.
