If you love rich, fudgy, melt-in-your-mouth chocolate desserts, these Marshmallow Brownies are the treat you’ve been looking for. Thick chocolate brownie batter is swirled with sweet, gooey marshmallow crème, creating decadent layers of texture—chewy, soft, and irresistibly gooey. Perfect for parties, potlucks, or cozy nights at home, this simple recipe delivers bakery-quality results without complicated steps or ingredients.

Why You’ll Love This Recipe

• Deep, fudgy chocolate flavor with a soft center and chewy edges
• Beautiful marshmallow swirls that add gooey sweetness
• No mixer required—easy for beginners
• Made with simple, budget-friendly ingredients
• Perfect for holidays, gatherings, or weeknight desserts
• A kid-approved treat thanks to its fun texture and sweetness

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

• 2 cups white granulated sugar
• 3 large eggs
• 1 egg yolk
• 0.5 cup unsalted butter, melted
• 2 tsp pure vanilla extract
• 0.5 cup canola or vegetable oil
• 0.75 cup all-purpose flour
• 1 cup unsweetened Dutch process cocoa powder
• 1.5 tbsp cornstarch
• 0.5 tsp salt
• 1 cup semi-sweet chocolate chips
• 1 cup marshmallow crème
• 9×13-inch baking pan
• Mixing bowls
• Whisk
• Rubber spatula
• Parchment paper
• Toothpick

Directions

1. Preheat the oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving an overhang for easy brownie removal. Lightly grease the parchment.
2. In a large bowl, whisk together the sugar, eggs, and egg yolk until well combined and slightly pale.
3. Add the melted butter, vanilla extract, and oil. Whisk until smooth.
4. In a separate bowl, sift together the flour, cocoa powder, cornstarch, and salt to remove lumps and ensure an even texture.
5. Fold the dry ingredients into the wet mixture using a spatula. Mix only until combined to keep the brownies fudgy.
6. Fold in the chocolate chips.
7. Pour half of the batter into the prepared pan.
8. Drop spoonfuls of marshmallow crème over the batter, then spread the remaining batter on top.
9. Use a knife to swirl the layers gently, creating a marbled effect.
10. Bake for 28–32 minutes, or until a toothpick inserted into the brownie portion (not the marshmallow) comes out with a few moist crumbs.
11. Let the brownies cool completely in the pan before slicing. This helps them set and ensures clean, neat cuts.

Servings and timing

This recipe makes about 16 large or 20 smaller brownies.
Prep time: 10 minutes
Bake time: 28–32 minutes
Cooling time: about 1 hour

Variations

• Add nuts such as chopped walnuts, pecans, or almonds for crunch.
• Create s’mores brownies by adding crushed graham crackers and mini marshmallows on top before baking.
• Swirl in caramel sauce instead of marshmallow crème for a salted caramel twist.
• Add spoonfuls of peanut butter for a chocolate-peanut combination.
• Use a 1:1 gluten-free flour blend for a gluten-free version.
• For a keto-friendly variation, use almond flour and replace sugar with a keto sweetener.

Storage/Reheating

• Store brownies in an airtight container at room temperature for up to 4 days.
• Refrigerate for up to 1 week for an extra fudgy texture.
• Freeze individually wrapped brownies for up to 2 months; thaw at room temperature.
• Reheat in the microwave for 10–15 seconds to restore gooey softness.

FAQs

Can I use mini marshmallows instead of marshmallow crème?

Yes. Replace 1 cup of marshmallow crème with 1½ cups of mini marshmallows, though the texture will be chunkier.

How do I make the brownies extra fudgy?

Reduce the flour to 0.5 cup and bake on the shortest end of the time range.

Can I double this recipe?

Yes. Use a larger pan or two 9×13 pans and extend the baking time by 5–8 minutes.

How can I make this recipe dairy-free?

Use dairy-free butter, a neutral plant oil, and dairy-free chocolate chips.

Why do my brownies sink in the center?

A slight sink means they’re extra fudgy. Excess sinking usually indicates underbaking.

Can I use natural cocoa powder instead of Dutch-process?

You can, but Dutch-process gives a deeper flavor and richer color.

How do I prevent overbaking?

Check the brownies at 28 minutes and remove when a toothpick comes out with moist crumbs—not dry.

Can I add more marshmallow crème?

Yes, but more crème may make slicing messier and increase bake time slightly.

Can I swirl the marshmallow on top instead of inside?

Yes. Swirl it over the top layer of batter for a more dramatic look.

Can I make this recipe ahead?

Yes. You can refrigerate the batter for 24 hours before baking. Let it sit at room temperature for 30 minutes before transferring to the oven.

Conclusion

These Marshmallow Brownies offer everything a chocolate lover could want—deep flavor, incredible fudginess, and irresistible gooey marshmallow ribbons. They’re easy to make, consistently delicious, and perfect for any celebration or casual treat. Whether served warm with ice cream or enjoyed on their own, these brownies always deliver a memorable and indulgent dessert experience.

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