Marshmallow Brownies

Why You’ll Love This Recipe

I’m obsessed with the texture of these brownies: chewy edges, gooey centers, and soft ribbons of melted marshmallow running throughout. They’re not just brownies — they’re a mashup of two favorites: chocolate fudge and marshmallow fluff. I can make them ahead, cut them into neat squares, and bring them to potlucks, parties, or just stash a few for my own late-night sweet cravings.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

• 2 cups white granulated sugar

• 3 large eggs

• 1 egg yolk

• 1/2 cup unsalted butter, melted

• 2 tsp pure vanilla extract

• 1/2 cup canola or vegetable oil

• 3/4 cup all-purpose flour

• 1 cup unsweetened Dutch-process cocoa powder

• 1 1/2 tbsp cornstarch

• 1/2 tsp salt

• 1 cup semi-sweet chocolate chips

• 1 cup marshmallow creme

Directions

1. I preheat my oven to 350°F (175°C) and line a 9×13-inch baking pan with parchment paper, leaving extra hanging over the sides for easy lifting. I lightly grease the parchment paper so nothing sticks.

2. In a large bowl, I whisk together the sugar, eggs, and egg yolk until the mixture is slightly pale and smooth. Then I add the melted butter, vanilla extract, and oil, whisking again until fully combined.

3. In a separate bowl, I sift together the flour, cocoa powder, cornstarch, and salt. This step ensures my brownies bake up with a smooth, lump-free texture.

4. I gently fold the dry mixture into the wet ingredients with a spatula, stirring just until everything is mixed — I don’t overmix to keep the brownies tender. Then I fold in the chocolate chips.

5. I pour half of the batter into the prepared pan and smooth it out. Then I drop spoonfuls of marshmallow creme over the batter, spacing them out across the surface.

6. I spread the remaining brownie batter on top, covering the marshmallow as evenly as I can. Using a butter knife, I gently swirl the batter and marshmallow together — just enough to create pretty patterns.

7. I bake the brownies for 28–32 minutes. To test for doneness, I insert a toothpick into the brownie part (not the marshmallow); it should come out with a few moist crumbs. The marshmallow will puff slightly and turn golden in spots.

8. I let the brownies cool completely in the pan before slicing. This helps them set up properly and gives me clean, gooey-centered squares.

Servings and timing

This recipe makes 16 brownie squares.
Prep time: 20 minutes
Cook time: 32 minutes
Total time: 52 minutes

Variations

Sometimes I sprinkle mini marshmallows on top during the last 5 minutes of baking for extra gooey flair. I’ve also added crushed graham crackers on top for a s’mores-inspired version. When I want a richer chocolate hit, I drizzle melted dark chocolate over the cooled brownies. Coconut oil makes a great substitute for canola oil and adds a light tropical twist.

storage/reheating

I store these brownies in an airtight container at room temperature for up to 4 days. If I want them extra fudgy, I refrigerate them — they firm up beautifully but stay moist. For a warm treat, I microwave a brownie square for 10–15 seconds to bring back that fresh-baked gooeyness.

FAQs

Can I use marshmallows instead of marshmallow creme?

Yes, but the texture will be slightly different. I’ve used mini marshmallows, pressing them lightly into the batter — they melt unevenly but still taste great.

Why add cornstarch to the batter?

Cornstarch helps create that chewy, soft texture I love in brownies. It also gives them a bit of lift without making them cakey.

Can I use natural cocoa instead of Dutch-process?

You can, but I prefer Dutch-process for its smoother, less acidic flavor. It also gives the brownies a richer, darker color.

How do I get clean brownie cuts?

I always let the brownies cool completely first. Then I use a sharp knife, wiping it clean between each slice. Sometimes I even chill the brownies before cutting for extra neat edges.

Can I freeze marshmallow brownies?

Yes, I wrap them tightly in plastic wrap and foil, then freeze for up to 2 months. When I want one, I thaw it at room temperature or warm it slightly in the microwave.

Conclusion

These Marshmallow Brownies bring together the best of both worlds — rich chocolate and gooey marshmallow — in one irresistible treat. I love how easy they are to make, and how they never fail to impress with their soft texture and sweet swirls. Whether I’m baking them for a crowd or just keeping a stash for myself, they always disappear fast.

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