These marshmallow brownies are chewy and fudgy with pockets and pools of gooey marshmallow. They’re easy to make, deeply chocolatey and the perfect way to elevate ordinary brownies into an indulgent treat.
If you love marshmallows, these marshmallow brownies are a must-try. They combine a rich chocolate base with generous dollops of marshmallow creme so you get soft, gooey pockets of sweetness throughout each bite. I tested variations using whole marshmallows, mini marshmallows and marshmallow creme (fluff) and found that marshmallow creme gives the best results: it stays soft and gooey instead of melting away. The method is straightforward and delivers consistently decadent brownies with a tender, fudgy crumb and glossy chocolate flavor.
Making Marshmallow Brownies
When marshmallows are mixed directly into batter they often melt and disappear during baking, leaving behind a sticky, hard sugar residue. To keep pockets of marshmallow intact and pillowy, this recipe relies on two important principles:
- Use marshmallow creme (fluff) rather than whole or mini marshmallows.
- Make a thick brownie batter so the marshmallow pockets are supported and don’t simply dissolve into the batter while baking.
The assembly is simple and forgiving. The goal is to distribute the marshmallow creme in several dollops, then cover most of it with remaining brownie batter. During baking the marshmallow will puff slightly and settle as the brownies cool, leaving soft, gooey ribbons inside the bars.
- Prep the pan. Preheat the oven to 350°F (180°C). Lightly grease an 8×8 inch (20×20 cm) pan and line it with parchment so there is an overhang on two sides. The parchment overhang makes it easy to lift the finished brownies from the pan and prevents sticking caused by melted marshmallow.
- Combine butter and sugar. In a large bowl, whisk together melted, slightly cooled unsalted butter and granulated sugar until the sugar is moistened and the butter no longer pools on top.
- Add eggs and vanilla. Beat in the vanilla extract, then add the eggs one at a time, beating after each addition until smooth and glossy.
- Incorporate melted chocolate. Stir in melted semi-sweet chocolate, scraping the bowl so the mixture is uniform. Melt chocolate slowly and gently to avoid scorching — use short microwave bursts or a double boiler.
- Fold dry ingredients. Sift together the all-purpose flour, cocoa powder and salt, then gently fold them into the chocolate mixture until just combined. The batter should be thick but still spreadable.
- Assemble the layers. Spoon roughly half the batter into the prepared pan and smooth it into an even layer. Drop spoonfuls of marshmallow creme (fluff) across the batter in several spots. It’s normal for the fluff not to cover the entire surface. Dot the remaining brownie batter between and slightly over the marshmallow dollops so the marshmallow is mostly enclosed.
- Bake. Bake in the center of the oven for about 35 minutes, or until the top appears set and a toothpick inserted into the brownie portion comes out with only a few moist crumbs (no raw batter). The marshmallow may puff during baking but will deflate as the brownies cool.
Recipe Tip
Allow the brownies to cool completely in the pan — ideally at least 3 hours — before slicing. Cooling lets the marshmallow set and prevents it from oozing out when you cut the bars. Use the parchment overhang to lift the whole slab onto a cutting board and slice with a sharp knife for neat squares.
More Marshmallow Treats to Love
- S’mores cookie bars
- Chocolate s’mores cookies
- Marshmallow Oreo brownies
Marshmallow Brownies
Equipment
- 8×8 inch (20×20 cm) pan
Ingredients
- ¾ cup unsalted butter (170 g), melted and cooled
- 1 cup granulated sugar (200 g)
- 2 teaspoons vanilla extract
- 2 large eggs
- 4 ounces semi-sweet chocolate (112 g), melted
- 1 cup all-purpose flour (125 g)
- ⅔ cup cocoa powder (53 g), sifted
- ¼ teaspoon salt
- 1 cup marshmallow fluff (marshmallow creme)
Instructions
- Preheat oven to 350°F (180°C). Lightly grease an 8×8 inch pan and line it with parchment paper so there is an overhang on two sides.
- In a large bowl, beat the melted, cooled butter with the granulated sugar until thoroughly combined and the butter no longer sits on top.
- Add the vanilla and beat in the eggs one at a time until the mixture is glossy and smooth.
- Stir in the melted chocolate, scraping the sides and bottom of the bowl to ensure even mixing. Melt chocolate slowly to avoid burning.
- Sift the flour, cocoa powder and salt together, then fold gently into the chocolate mixture until just combined. The batter should be thick and fudgy.
- Spoon about half of the batter into the prepared pan and smooth into an even layer. Drop spoonfuls of marshmallow fluff across the surface. Dot the remaining batter between and over the marshmallow dollops so the marshmallow is mostly covered.
- Bake for about 35 minutes, or until the top is set and a toothpick inserted into a brownie portion comes out with moist crumbs but no raw batter. The marshmallow will puff and then settle as it cools.
- Cool completely in the pan, at least 3 hours, then use the parchment overhang to lift the slab out and slice into squares with a sharp knife.
Notes
- Marshmallow creme: Do not substitute with mini or regular marshmallows; they will melt and disappear during baking and won’t create the same soft pockets.
- Storage: Store cooled brownies in an airtight container at room temperature for up to 4 days. For longer storage, freeze individual squares wrapped tightly.
- Yield: This recipe makes 9 large brownies. For smaller portions, cut each piece in half to yield 18 squares.
Nutrition
Carbohydrates: 54 g,
Protein: 5 g,
Fat: 22 g,
Sugar: 36 g