If your childhood had a sweet spot, it was probably filled with peanut butter, marshmallow fluff, and plenty of sticky-fingered smiles. Fluffernutter Bars capture that nostalgic joy with a rich peanut butter cookie base, a dreamy marshmallow layer, and a golden crumbly topping. Every bite is the perfect blend of chewy softness and gooey sweetness, transforming a lunchbox favorite into an irresistible dessert you’ll want to share with everyone—if you can resist keeping them all to yourself! Trust me, these bars are pure magic.

Fluffernutter Bars Recipe - Recipe Image

Ingredients You’ll Need

These Fluffernutter Bars are proof that simple pantry staples can deliver over-the-top flavor. Each ingredient is chosen for its power to bring out that pillowy-soft, rich, and unmistakably cozy vibe. Here’s what you’ll need and why it matters:

Unsalted butter (1/2 cup, softened): The foundation for super tender, melt-in-your-mouth bars. Room temperature butter creams beautifully for a light dough.
Granulated sugar (1/2 cup): Adds essential sweetness and helps form the perfect chewy texture.
Brown sugar (1/2 cup, packed): Infuses every bite with caramel notes and keeps the bars deliciously soft.
Egg (1 large): Binds everything together while promoting a rich, cakey structure.
Vanilla extract (1 teaspoon): Just a splash brings warmth and complexity to both the peanut butter and marshmallow flavors.
Creamy peanut butter (3/4 cup): This is the heart and soul of Fluffernutter Bars—smooth, nutty, and irresistible!
All-purpose flour (1 1/4 cups): The backbone of the bars, providing enough structure to cradle that dreamy marshmallow layer.
Baking powder (1/2 teaspoon): Gives rise to the dough, ensuring every bar is soft without being too dense.
Salt (1/4 teaspoon): Balances the sweetness and rounds out flavors (don’t skip it—even in desserts!).
Marshmallow creme (1 cup): Fluff brings the gooey, sticky center—the iconic “fluffer” in Fluffernutter Bars!

How to Make Fluffernutter Bars

Step 1: Prep Your Pan and Preheat

Set yourself up for success by preheating the oven to 350°F (175°C). Lightly grease an 8×8-inch baking pan or line it with parchment paper for the easiest possible release. The parchment makes lifting and slicing an absolute breeze—trust me, it’s worth the extra step.

Step 2: Cream the Butter and Sugars

Grab a large mixing bowl and an electric mixer. Beat the softened butter, granulated sugar, and brown sugar together until the mixture turns pale and fluffy—about 2-3 minutes. This creaming process traps air, ensuring your Fluffernutter Bars are never heavy or greasy.

Step 3: Add Egg, Vanilla, and Peanut Butter

Mix in the egg and vanilla extract until the dough looks smooth and cohesive. Next, swirl in your creamy peanut butter—watch as the batter takes on that signature nutty aroma that makes everyone’s heart skip a beat.

Step 4: Combine Dry Ingredients

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt. This ensures even distribution and prevents clumps (no one wants a mouthful of baking powder). Gently add the dry mixture to your wet ingredients, mixing just until a soft dough forms.

Step 5: Layer the Dough and Marshmallow Creme

Spread about two-thirds of your dough into the bottom of the prepared pan, smoothing it into an even layer that reaches all four corners. Dollop the marshmallow creme by the spoonful onto the dough, then use a spatula to gently and evenly swirl it across the surface. Don’t worry about perfection—the magic is in the marbled effect!

Step 6: Top and Bake

Crumble the remaining dough over the marshmallow layer in small pieces. Lightly press them in so they’ll bake into a delicious patchwork topping. Slide the pan into the oven and bake for 25–28 minutes, or until the bars are golden and set around the edges (the center might jiggle just a bit, but will firm up as it cools).

Step 7: Cool and Slice

Let your Fluffernutter Bars cool completely in the pan—this step is crucial for clean slicing and perfect layers. For extra tidy squares, chill the pan in the fridge for 30 minutes before cutting into 16 equal bars. Prepare for oohs and aahs!

How to Serve Fluffernutter Bars

Garnishes

Give your Fluffernutter Bars that bakery-café touch with a few thoughtful garnishes. Try a drizzle of melted chocolate, a dusting of powdered sugar, or a sprinkle of flaky sea salt to intensify both sweetness and crunch. Even a handful of mini peanut butter chips pressed on top before baking is a showstopper move.

Side Dishes

Balance out the rich sweetness of the Fluffernutter Bars with a glass of cold milk (classic for a reason!), unsweetened iced tea, or strong coffee. For an extra-special treat, serve alongside fresh berries or a scoop of vanilla ice cream—warm bars and cool ice cream are pure dessert bliss together.

Creative Ways to Present

Think beyond the bar! Stack Fluffernutter Bars on a tiered stand for a stunning dessert table centerpiece, wrap individual bars in parchment for lunchbox treats, or tuck squares into a picnic basket. For a party, cut into bite-size cubes and spear with toothpicks for fluffernutter “bites”—adorable and irresistible.

Make Ahead and Storage

Storing Leftovers

Keep any leftover Fluffernutter Bars (if there are any!) in an airtight container at room temperature for up to 3 days. They’ll stay soft and chewy, with that signature gooey center, making them perfect as a grab-and-go treat or a sweet finish for unexpected guests.

Freezing

Want to enjoy Fluffernutter Bars later? Freeze individual bars, tightly wrapped in plastic, then place them in a zip-top freezer bag. They’ll stay tasty for up to two months. Thaw at room temperature whenever a late-night peanut butter craving strikes.

Reheating

If you love a touch of warm, gooey marshmallow, microwave a bar for 10–15 seconds. This quick zap softens the layers and brings back just-baked aroma. Be sure not to overheat—just a little warmth goes a long way!

FAQs

Can I double the recipe for a larger crowd?

Absolutely! Just use a 9×13-inch pan and double all the ingredients. Baking time may increase slightly, so keep an eye and test doneness around the 30–35 minute mark.

Can I use crunchy peanut butter instead of creamy?

You can, and it’ll add a bit of texture to your Fluffernutter Bars. Just be aware the bars may be slightly less moist, so you might want to add an extra tablespoon of butter if your peanut butter is very thick.

What’s the best way to cut clean bars?

For the cleanest slices, cool the bars completely, then chill in the fridge for at least 30 minutes before slicing with a sharp knife. Wipe the blade between cuts for perfect edges!

Can I add chocolate chips or other mix-ins?

Yes! Feel free to stir up to 1/2 cup chocolate chips, white chocolate chunks, or chopped roasted peanuts into the dough. You can even sprinkle some on top before baking for a fun twist.

Do I have to use marshmallow creme, or can I use mini marshmallows?

Marshmallow creme gives the signature gooey layer, but if you’re in a pinch, mini marshmallows scattered over the base layer work in a pinch—just be aware the texture will be stretchier and might caramelize more in the oven.

Final Thoughts

I honestly can’t wait for you to try these Fluffernutter Bars. They’re comfort food at its finest—a little bit nostalgic, a lot delicious, and sure to spark joy with everyone who takes a bite. Go ahead and treat yourself (and someone you love) to a batch soon—you’ll see why these bars are absolutely irresistible!