How to Make Marshmallow Brownies: A Step-by-Step Guide

Indulge in the perfect combination of rich, fudgy brownies swirled with creamy marshmallow goodness! These Ultimate Marshmallow Brownies deliver an irresistible texture that’s both decadent and nostalgic, reminiscent of campfire s’mores in brownie form.

Why You’ll Love This Recipe:

These Ultimate Marshmallow Brownies are absolutely irresistible for several compelling reasons. The recipe creates incredibly fudgy brownies with a dense, moist crumb that melts in your mouth, while the marshmallow creme adds a delightfully gooey texture and sweet vanilla flavor that perfectly complements the rich chocolate. The combination of melted butter and oil ensures these brownies stay moist for days, and the addition of an extra egg yolk creates that coveted fudgy consistency that brownie lovers crave. Plus, they’re surprisingly easy to make with simple pantry ingredients, requiring no special equipment or complicated techniques. Whether you’re serving them at a family gathering, bake sale, or simply treating yourself, these marshmallow brownies deliver bakery-quality results every time.

Ingredients You’ll Need:

• 2 cups White granulated sugar
• 3 Large eggs
• 1 Egg yolk
• ½ cup Unsalted butter, melted
• 2 tsp Pure vanilla extract
• ½ cup Oil (canola or vegetable)
• ¾ cup All-purpose flour
• 1 cup Unsweetened cocoa powder (Dutch process preferred)
• 1½ Tbsp Cornstarch
• ½ tsp Salt
• 1 cup Semi-sweet chocolate chips
• 1 cup Marshmallow creme

How to Make Best Marshmallow Brownies Recipe:

Step-by-Step Instructions:

Step 1: Prepare Your Pan and Oven Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving some overhang for easy removal. Lightly grease the parchment with cooking spray or butter.

Step 2: Mix the Wet Ingredients In a large mixing bowl, whisk together the granulated sugar, whole eggs, and egg yolk until well combined and slightly lightened in color, about 2-3 minutes. Add the melted butter, vanilla extract, and oil, whisking until the mixture is smooth and glossy.

Step 3: Combine Dry Ingredients In a separate bowl, sift together the all-purpose flour, cocoa powder, cornstarch, and salt. This ensures no lumps and creates a smoother batter.

Step 4: Create the Brownie Batter Gradually fold the dry ingredients into the wet mixture using a wooden spoon or rubber spatula. Mix just until combined—don’t overmix, as this can lead to tough brownies. Fold in the chocolate chips until evenly distributed.

Step 5: Add the Marshmallow Layer Pour the brownie batter into your prepared pan and spread evenly. Drop spoonfuls of marshmallow creme over the surface of the batter. Using a knife or skewer, gently swirl the marshmallow creme through the brownie batter, creating beautiful marbled patterns. Don’t overmix—you want distinct swirls.

Step 6: Bake to Perfection Bake for 35-40 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs (not completely clean). The marshmallow areas may puff slightly and turn golden.

Step 7: Cool and Serve Allow the brownies to cool completely in the pan before lifting out using the parchment paper overhang. Cut into squares and serve.

Helpful Tips:

Room temperature ingredients blend more easily, so take your eggs out about 30 minutes before baking. When melting butter, let it cool slightly before adding to prevent cooking the eggs. Dutch process cocoa powder creates richer flavor and better color, but regular unsweetened cocoa works too. Don’t overbake these marshmallow brownies—they continue cooking from residual heat even after removing from the oven. For clean cuts, use a sharp knife wiped clean between cuts, or chill the brownies for 30 minutes before slicing. The cornstarch helps create that perfect fudgy texture by preventing the brownies from becoming too dense. For extra indulgence, warm individual squares in the microwave for 10-15 seconds before serving.

Details:

Prep Time: 15 minutes
Cook Time: 35-40 minutes
Total Time: 50-55 minutes
Servings: 24 brownies
Difficulty: Easy
Category: Dessert
Method: Baking
Cuisine: American

Notes:

These Ultimate Marshmallow Brownies are best enjoyed within the first few days of baking when the marshmallow swirls are at their gooiest. The recipe can easily be halved and baked in an 8×8-inch pan for smaller batches—just reduce the baking time to 25-30 minutes. If you prefer extra chocolatey brownies, substitute mini marshmallows for half the marshmallow creme and fold them directly into the batter. For a more intense chocolate flavor, add 1-2 tablespoons of espresso powder to the dry ingredients. The brownies will appear slightly underbaked when you remove them from the oven, but they’ll continue to set as they cool, resulting in that perfect fudgy texture.

Frequently Asked Questions:

Can I use regular marshmallows instead of marshmallow creme? Yes! You can substitute 2 cups of mini marshmallows for the marshmallow creme. Fold half into the batter and sprinkle the rest on top before baking.

Why are my brownies too dense? Overmixing the batter after adding flour can create dense brownies. Mix just until the ingredients are combined, and don’t worry if the batter looks slightly lumpy.

Can I make these brownies ahead of time? Absolutely! These marshmallow brownies actually improve in flavor after sitting overnight. Store covered at room temperature for up to 4 days.

What’s the best way to get clean brownie squares? Chill the brownies for 30 minutes, then use a sharp knife wiped clean between each cut. You can also run the knife under warm water and dry it between cuts.

Can I freeze these brownies? Yes! Wrap individual squares in plastic wrap and freeze for up to 3 months. Thaw at room temperature or warm in the microwave for a few seconds.

Storage Instructions:

Store your Ultimate Marshmallow Brownies covered at room temperature for up to 4 days. For longer storage, individually wrap squares in plastic wrap and place in an airtight container in the refrigerator for up to 1 week. The marshmallow swirls may firm up slightly when chilled, but they’ll soften again at room temperature. For freezing, wrap individual brownies in plastic wrap, then place in a freezer-safe container or bag for up to 3 months. When ready to enjoy, thaw at room temperature for about 30 minutes, or warm briefly in the microwave for that just-baked taste and texture.

Related Recipes:

Looking for more decadent brownie variations? Try our Peanut Butter Swirl Brownies for a nutty twist, or indulge in our Triple Chocolate Brownies for serious chocolate lovers. If you enjoy the marshmallow flavor, our S’mores Barscombine graham crackers, chocolate, and marshmallows in an irresistible layered dessert. For a lighter option, check out our Chocolate Chip Cookie Bars that deliver similar satisfaction with a different texture.

Conclusion:

These Best Marshmallow Brownies truly live up to their name, delivering the perfect balance of rich chocolate and sweet marshmallow in every bite. The combination of fudgy texture and gooey marshmallow swirls creates an unforgettable dessert that’s sure to become a family favorite. Whether you’re a seasoned baker or just starting out, this recipe’s straightforward instructions and reliable results make it a go-to choice for any occasion. The beauty of these Ultimate Marshmallow Brownies lies not just in their incredible taste, but in their versatility—they’re perfect for potlucks, bake sales, casual family dinners, or special celebrations. With simple ingredients and foolproof techniques, you’ll have a batch of bakery-quality brownies that will have everyone asking for the recipe. So preheat that oven, gather your ingredients, and get ready to create some truly magical marshmallow brownies that will satisfy even the most discerning sweet tooth!

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