Fluffernutter Brownies

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A rich, fudgy brownie meets the gooey magic of marshmallow fluff and the nutty depth of creamy peanut butter — that’s the irresistible charm of Fluffernutter Brownies. These decadent squares strike the perfect balance between chewy and soft, with swirls of melty peanut butter and pockets of sweet fluff peeking through the dark chocolate base. Every bite is indulgent yet nostalgic, echoing the classic fluffernutter sandwich many grew up loving.

Perfect for bake sales, cozy gatherings, or anytime you need a show-stopping dessert, Fluffernutter Brownies are as impressive to look at as they are delicious to eat. They’re simple enough for beginners but deliver the kind of flavor complexity that keeps everyone reaching for just one more square. Whether served warm with a scoop of ice cream or packed into a lunchbox for a sweet surprise, these brownies are guaranteed crowd-pleasers.

Why You’ll Love This Fluffernutter Brownies Recipe

• Combines the best of chocolate, peanut butter, and marshmallow in one bite
• No mixer required — just simple ingredients and big flavor
• Kid-friendly and adult-approved
• Great for making ahead or freezing for later
• Customizable with crunchy peanut butter or extra chocolate chips

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Preparation Phase & Tools to Use (Essential Tools and Equipment and Their Importance)

To make flawless Fluffernutter Brownies, you’ll want a few key tools:

• 8×8-inch baking pan: The ideal size for thick, gooey brownies without overbaking the edges.
• Parchment paper: Helps lift the brownies cleanly out of the pan and makes cleanup a breeze.
• Mixing bowls: One large bowl for the wet ingredients, another smaller for the dry ones. This keeps the mixing process clean and efficient.
• Whisk & spatula: A whisk ensures your eggs and sugars are thoroughly combined, while the spatula is essential for folding in the flour and swirling in the peanut butter and fluff.
• Microwave-safe bowl or small saucepan: For gently melting the butter and chocolate together.

Each of these tools supports ease, accuracy, and a smooth workflow, making the process as enjoyable as the final bite.

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Preparation Tips

Use room temperature eggs for a smoother batter and better texture. When melting butter and chocolate, go slow — either over low heat or in short microwave bursts to prevent scorching. Always line your pan with parchment, allowing some overhang on the sides for easy lifting. Once you swirl in the peanut butter and marshmallow fluff, avoid overmixing — you want ribbons and pockets of flavor, not an even blend. Lastly, let the brownies cool completely before cutting to get clean, perfect squares with defined edges.

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Ingredients for this Fluffernutter Brownies Recipe

• 1/2 cup (1 stick) unsalted butter
• 6 oz semi-sweet chocolate, chopped (or chocolate chips)
• 3/4 cup granulated sugar
• 1/4 cup brown sugar (light or dark)
• 2 large eggs, room temperature
• 1 teaspoon pure vanilla extract
• 1/2 cup all-purpose flour
• 2 tablespoons unsweetened cocoa powder
• 1/4 teaspoon salt
• 1/3 cup creamy peanut butter (plus more for swirling, if desired)
• 1/3 cup marshmallow fluff or creme (plus more for swirling)
• Optional: 1/4 cup mini chocolate chips for added texture

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Step 1: Preheat and Prepare

Preheat your oven to 350°F (175°C). Line an 8×8-inch square baking pan with parchment paper, leaving a bit of overhang on the sides to lift the brownies out later. Lightly grease the paper with nonstick spray or butter for easier release.

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Step 2: Melt Butter and Chocolate

In a microwave-safe bowl or small saucepan, combine the butter and semi-sweet chocolate. Heat in 30-second increments (if microwaving), stirring in between until melted and smooth. Let it cool slightly before the next step to avoid cooking the eggs.

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Step 3: Mix Wet Ingredients

Pour the melted chocolate mixture into a large mixing bowl. Whisk in the granulated sugar and brown sugar until well combined. Add eggs one at a time, beating well after each addition. Stir in the vanilla extract until the batter looks thick, shiny, and cohesive.

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Step 4: Fold in Dry Ingredients

In a separate bowl, whisk together the flour, cocoa powder, and salt. Gently fold the dry ingredients into the wet batter using a spatula. Mix just until you no longer see streaks of flour — do not overmix to keep the brownies tender.

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Step 5: Add Peanut Butter and Fluff

Pour half of the brownie batter into the prepared pan and spread evenly. Drop spoonfuls of peanut butter and marshmallow fluff over the batter. Swirl gently with a butter knife. Pour the remaining batter over the top and repeat the swirling with additional peanut butter and fluff as desired.

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Step 6: Bake

Place the pan in the oven and bake for 28–32 minutes, or until the center is set and a toothpick inserted comes out with a few moist crumbs. Avoid overbaking to retain a fudgy texture.

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Step 7: Cool and Slice

Allow the brownies to cool in the pan on a wire rack for at least 30 minutes. Use the parchment paper overhang to lift the slab out, then transfer to a cutting board. Slice into 12 squares using a sharp knife. Clean the knife between cuts for neater edges.

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Notes

These brownies taste even better the next day as the flavors deepen and the texture becomes fudgier. If you like a gooier center, bake on the shorter end of the time range and let them cool fully before slicing. For a firmer brownie that’s easier to transport, extend the bake time by 2-3 minutes. You can also add chopped peanuts or a sprinkle of flaky sea salt on top for extra crunch and contrast.

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Watch Out for These Mistakes While Cooking

• Overbaking: It’s easy to overbake brownies, resulting in a dry, cakey texture. Always test for doneness with a toothpick; moist crumbs are okay, but no wet batter.
• Overmixing the batter: Once you add the flour, stir just until incorporated. Overmixing develops gluten, which can make the brownies tough.
• Not cooling the melted chocolate enough: Hot chocolate can scramble the eggs, so make sure the mixture is warm, not hot, before adding eggs.
• Skipping parchment paper: This makes removing brownies much harder and can cause sticking, especially with gooey layers.
• Uneven swirling: Too much swirling can mix everything together and muddy the distinct flavors. Swirl gently for the best visual and taste contrast.

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Storage Instructions

Once completely cooled, store Fluffernutter Brownies in an airtight container at room temperature for up to 3 days. For longer storage, refrigerate them for up to a week, though this may firm them up slightly. To freeze, wrap individual squares tightly in plastic wrap and place in a freezer-safe bag or container; they’ll keep well for up to 2 months. Thaw at room temperature or gently warm in the microwave before serving.

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Estimated Nutrition (Per Serving — Based on 12 Brownies)

• Calories: 290
• Fat: 16g
• Saturated Fat: 8g
• Unsaturated Fat: 6g
• Trans Fat: 0g
• Cholesterol: 55mg
• Sodium: 95mg
• Carbohydrates: 34g
• Fiber: 2g
• Sugar: 23g
• Protein: 4g
• Serving Size: 1 brownie

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Frequently Asked Questions

Can I use crunchy peanut butter instead of creamy?

Yes! Crunchy peanut butter adds a lovely texture. Just be sure to swirl it gently, as it can be thicker.

Can I double the recipe?

Absolutely. Double all ingredients and bake in a 9×13-inch pan. Increase baking time to about 35–40 minutes.

What’s the best way to swirl in the fluff and peanut butter?

Use a butter knife or skewer and gently make figure-eight patterns through the batter. Don’t overdo it.

Can I use store-bought brownie mix?

You can, but homemade gives you more control over the richness and texture. If using a mix, prepare it as directed and swirl in peanut butter and fluff before baking.

How do I get clean brownie cuts?

Let brownies cool fully, then use a sharp knife wiped clean between each cut. Chilling the brownies slightly also helps.

Can I make these gluten-free?

Yes. Use a 1:1 gluten-free baking flour. The texture may vary slightly, but they’ll still taste great.

Why did my fluff melt completely?

This can happen if you swirl it too deeply or use too little. Try dropping larger dollops on top and gently swirling only the surface.

Are these brownies very sweet?

They are rich and sweet, thanks to the chocolate and marshmallow. You can cut back slightly on the sugar if desired, but expect a change in texture.

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Conclusion

Fluffernutter Brownies combine the best parts of a classic peanut butter and marshmallow sandwich with the indulgent richness of homemade chocolate brownies. With their gooey swirls, deep flavor, and chewy texture, they’re a true crowd-pleaser for any occasion. Easy to make and even easier to love, these brownies deliver both comfort and creativity in every bite.

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