These marshmallow brownies are chewy and fudgy with pools of gooey marshmallow throughout. They’re simple to make, super decadent and the perfect way to elevate classic brownies.
If you’re a marshmallow fan, these marshmallow brownies are a must-try. They combine a rich, chocolatey brownie with generous pockets of marshmallow that stay soft and gooey after baking. I tested versions using full-size marshmallows, mini marshmallows, and marshmallow creme (fluff). Marshmallow creme proved essential for achieving those oozy, pillowy pockets that don’t simply melt away into the batter. The method is straightforward and the result is deeply satisfying—fudgy, chewy brownies studded with marshmallow bliss.
Making Marshmallow Brownies
Marshmallows are notorious for disappearing into baked goods. When you add standard marshmallows or minis to cookie dough or brownie batter, they often melt and leave behind a sticky, crystallized sugar pocket instead of a soft marshmallow center. To preserve distinct pockets of marshmallow in the finished brownies, two things matter most:
- Use marshmallow creme (fluff) rather than whole marshmallows or minis.
- Keep the brownie batter relatively thick; a thinner batter encourages the marshmallow to disperse and dissolve during baking.
The assembly and baking are uncomplicated when you follow a few simple steps. Below is a clear, approachable method to get consistent, fudgy brownies with visible, gooey marshmallow pockets.
- Prep. Preheat the oven to 350°F (180°C). Lightly grease an 8×8 inch (20×20 cm) pan and line it with parchment paper, leaving an overhang on the sides for easy removal. Lining the pan is important because marshmallow can make brownies stick to the pan if you skip it.
- Beat the butter and sugar. Combine melted, cooled butter with granulated sugar in a large bowl and mix until the butter is fully incorporated and no longer sitting on top. This helps ensure a smooth, even texture.
- Add eggs and vanilla. Add the eggs one at a time, beating well after each addition, then stir in the vanilla extract.
- Mix in melted chocolate. Fold melted semi-sweet chocolate into the batter. Use chocolate around 50–60% cocoa for a balanced flavor. Melt chocolate gently—either in a double boiler or in short bursts in the microwave, stirring between intervals—to avoid burning.
- Sift dry ingredients and combine. Sift together the flour, cocoa powder, and salt to remove lumps, then fold into the wet ingredients gently until just combined. Keep the batter thick rather than thin.
- Assemble. Spoon about half (or slightly more) of the brownie batter into the prepared pan and smooth it into an even layer. Drop spoonfuls of marshmallow fluff across the batter; it won’t cover the surface completely and that’s fine. Dot the remaining brownie batter in between and over the marshmallow dollops. Quickly spread the batter into an even layer—some marshmallow may remain exposed, which will puff during baking.
- Bake. Bake in the center of the preheated oven for about 35 minutes, until the top appears set and a toothpick inserted into the brownie portion comes out without raw batter. The marshmallow will puff up in the oven and then settle as the brownies cool.
Recipe Tip
Allow the brownies to cool completely in the pan for at least three hours before slicing. Cooling fully helps the marshmallow settle and prevents it from oozing out when you cut the brownies.
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)
- ¼ teaspoon salt
- 1 cup marshmallow fluff (marshmallow creme)
Instructions
- Preheat the oven to 350°F (180°C). Lightly grease an 8×8 inch pan and line it with parchment paper so you have an overhang for lifting the brownies out.
- In a large bowl, beat the melted, cooled butter and sugar together until the butter is fully incorporated and doesn’t sit on top.
- Add vanilla and beat in the eggs one at a time, mixing well after each addition.
- Stir in the melted chocolate, scraping the bowl to ensure even distribution. Melt chocolate slowly to avoid scorching.
- Sift the flour, cocoa, and salt into the bowl and gently fold until just combined. Keep the batter thick.
- Spoon about half the batter into the prepared pan and smooth into an even layer. Drop dollops of marshmallow fluff across the batter, then add remaining batter in between and over the dollops. Spread carefully—some marshmallow may remain exposed.
- Bake for about 35 minutes or until the top is set and a toothpick inserted into the brownie portion comes out clean of raw batter. The marshmallow will puff during baking and collapse as it cools.
- Cool completely in the pan. Use the parchment overhang to lift the slab out, then slice with a sharp knife into squares.
Notes
- Marshmallow Creme: Use marshmallow creme (fluff) rather than whole marshmallows or mini marshmallows; whole marshmallows tend to melt away and won’t create the same soft pockets.
- Storage: Store brownies in an airtight container at room temperature for up to four days.
- Portions: The recipe yields nine large squares, but you can cut them into 18 smaller servings if desired.
Nutrition
Estimated per serving (based on 9 large brownies): Calories: 418 kcal; Carbohydrates: 54 g; Protein: 5 g; Fat: 22 g. These values are approximate.