Fluffernutter Brownies

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There’s something magical about the combination of peanut butter, chocolate, and gooey marshmallow. Fluffernutter Brownies take that classic flavor mash-up to the next level, fusing fudgy chocolate brownies with swirls of peanut butter and pockets of melty marshmallow. Every bite is a little bit nostalgic and a whole lot delicious.

These brownies aren’t just a treat—they’re a showstopper. Perfect for bake sales, family gatherings, or anytime you want a rich, satisfying dessert that feels both comforting and a little bit indulgent. If you love s’mores, peanut butter cups, or anything with a gooey center, these are about to become your new obsession.

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Why You’ll Love This Fluffernutter Brownies Recipe

The contrast between the chewy chocolate base, the salty-sweet peanut butter, and the molten pockets of marshmallow makes these brownies irresistible. Plus, you don’t need any fancy equipment or techniques—just a few bowls and pantry staples.

These brownies are ultra-fudgy, visually stunning, and easy to transport. Whether you serve them at a potluck or pack them in a lunchbox, expect rave reviews and requests for the recipe.

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What Kind of Peanut Butter Works Best?

For the best results, use creamy peanut butter (not the natural kind that separates). It gives you the smoothest swirls and ensures every bite is perfectly rich. Chunky peanut butter will also work if you want some added texture, but avoid natural peanut butter since the extra oil can cause greasy, uneven pockets in your brownies.

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Ingredients for the Fluffernutter Brownies

These brownies get their iconic flavor from a handful of everyday ingredients, each playing a key role in the final texture and taste.

• Unsalted Butter: Provides richness and helps create that classic fudgy brownie crumb. Melting the butter ensures a denser, chewier texture.
• Granulated Sugar: Sweetens the batter and helps develop a shiny, crackly top.
• Brown Sugar: Adds depth and a subtle caramel undertone, making the brownies extra moist.
• Large Eggs: Bind everything together and add structure while keeping the brownies rich.
• Vanilla Extract: Enhances all the flavors and adds warmth to the chocolate.
• All-Purpose Flour: The backbone of the brownies—too much and they’ll be cakey, so measure carefully.
• Unsweetened Cocoa Powder: Delivers the intense chocolatey base. Use Dutch-processed for extra richness if you have it.
• Salt: Balances sweetness and sharpens the flavors.
• Creamy Peanut Butter: For that signature fluffernutter swirl—choose a no-stir, shelf-stable variety for best results.
• Mini Marshmallows: Scatter them throughout for gooey, toasty pockets in every slice.
• Semi-Sweet Chocolate Chips: Optional, but add even more chocolate intensity and melty bites.

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How To Make the Fluffernutter Brownies

Step 1: Prep and Preheat

Preheat your oven to 350°F (175°C). Line a 9×9-inch baking pan with parchment paper, leaving an overhang for easy removal later. Lightly grease the parchment.

Step 2: Make the Brownie Batter

In a large microwave-safe bowl, melt 1 cup (226g) unsalted butter. Whisk in 1 cup (200g) granulated sugar and 1/2 cup (100g) packed brown sugar until glossy. Add 3 large eggs, one at a time, whisking well after each addition. Stir in 2 teaspoons vanilla extract.

Sift in 3/4 cup (90g) all-purpose flour, 3/4 cup (65g) unsweetened cocoa powder, and 1/2 teaspoon salt. Gently fold with a spatula until just combined (don’t overmix).

Step 3: Layer and Swirl

Spread half the brownie batter evenly into your prepared pan. Dollop 1/2 cup (125g) creamy peanut butter in spoonfuls over the batter, then swirl gently with a knife. Sprinkle 1 1/2 cups (75g) mini marshmallows over the peanut butter. Top with the remaining brownie batter and gently smooth. Add another 1/4 cup (60g) peanut butter in dollops, swirling once more. For extra decadence, sprinkle 1/2 cup (90g) semi-sweet chocolate chips on top.

Step 4: Bake

Bake for 32-36 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs (don’t overbake; you want fudgy brownies!). If needed, tent loosely with foil at the 25-minute mark to prevent over-browning.

Step 5: Cool and Cut

Let the brownies cool completely in the pan on a wire rack. Lift them out using the parchment, then cut into 16 squares. Serve and enjoy!

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Serving and Storing Fluffernutter Brownies

This recipe yields 16 generous brownies, perfect for sharing with family and friends. It comfortably feeds 8-10 people as a dessert, or more if serving as a bite-sized snack at a party.

Store leftovers in an airtight container at room temperature for up to 4 days. For longer storage, refrigerate for up to a week or freeze (well-wrapped) for up to 2 months—just thaw and bring to room temp before serving to get that gooey texture back.

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What to Serve With Fluffernutter Brownies

1. A tall glass of cold milk

Classic and always perfect with brownies.

2. Fresh strawberries or raspberries

The tartness balances the rich, sweet flavors.

3. A scoop of vanilla ice cream

For ultimate indulgence, top a warm brownie with a scoop of vanilla ice cream.

4. Rich Mac and Cheese

A comforting main to follow up with dessert—get the recipe here.

5. Peanut Butter Icing

Spread a little extra on top or drizzle for peanut butter lovers—peanut butter icing recipe.

6. S’mores Cookie Bars

Pair with these for a full marshmallow-chocolate spread—s’mores cookie bars.

7. Hot Coffee or Espresso

Bitterness balances the sweetness and makes the chocolate shine.

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Frequently Asked Questions

1. Can I double this recipe for a 9×13-inch pan?
Yes! Double all ingredients and bake in a 9×13-inch pan for 36-40 minutes. Check for doneness at 36 minutes with a toothpick.

2. Can I use natural peanut butter?
Natural peanut butter isn’t recommended, as the oil separation affects texture and swirling. Stick to creamy, no-stir peanut butter for best results.

3. How do I get clean cuts on gooey brownies?
Let the brownies cool fully, then use a hot knife (run under hot water and wiped dry) to make neat, clean slices.

4. What’s the best way to freeze these brownies?
Cut cooled brownies into squares, wrap individually in plastic, then store in a freezer-safe bag for up to 2 months. Thaw at room temperature before enjoying.

5. Can I make these gluten-free?
Yes, use a 1:1 gluten-free baking flour in place of all-purpose flour. Texture may vary slightly but results are still delicious.

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Save This Pin For Later

📌 Save this recipe to your Pinterest dessert board so you can come back to it any time.
And let me know in the comments how yours turned out. Did you add extra peanut butter or try a different chocolate? Did you toast the marshmallows on top for an even gooier effect?

I love hearing how others make these recipes their own. Questions are welcome too, let’s help each other bake smarter. For more inspiration and daily recipes, check out my Michelle Recipes | LadySavory on Pinterest!

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Conclusion

Fluffernutter Brownies are a celebration of everything comforting—rich chocolate, creamy peanut butter, and sweet, toasty marshmallow all in one decadent bite. With just a few ingredients and simple steps, you can whip up a dessert that looks impressive and tastes even better. Try them for your next gathering or as a special treat for yourself—these are brownies that everyone will remember!

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Try more gooey dessert recipes like these S’mores Cookie Bars, Peanut Butter Icing, and a Rich Mac and Cheese for the perfect cozy meal.

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