Fluffernutter Bars are peanut butter bars filled with a layer of marshmallow fluff. These bars are a perfectly sweet, ooey gooey treat! If you prefer cookies, I also have a fluffernutter cookie recipe that you will love.

Fluffernutter Bars from Overhead Showing the Marshmallow that Spilled Up Over the Peanut Butter Bar.

Fluffernutter Bars

Everything is coming up fluffernutter! As soon as I made my cookies based on the popular peanut butter and marshmallow sandwich, I had to venture into dessert bars and even fluffernutter fudge. You can make all three of my yummy fluffernutter desserts to add to your Christmas dessert charcuterie board! These bars start with the ingredients from my fluffernutter cookies. Then, it’s all about the marshmallow fluff (creme) placed in between the layers of dough. For a no-bake treat with the same delicious flavors, try my Fluffernutter Rice Krispie Bars, too!

Adding Marshmallow Fluff to Raw Peanut Butter Cookie Batter in a Pan.


Peanut Butter: I used creamy peanut butter in these bars, but could also use crunchy peanut butter.

Marshmallow Fluff: Also known as marshmallow creme, this is an ooey-gooey spreadable concoction with a marshmallow taste. If you don’t have any on hand, make your own!

Room Temperature Ingredients: Using room temperature ingredients (specifically butter and eggs) will help you get the best results when baking these bars (and other recipes that call for room temperature ingredients). Butter is at room temperature at 65°F. Don’t put it in the microwave to soften it; simply cut it up into small pieces and let it sit out if you forgot to take it out of the refrigerator.

Adding Peanut Butter Cookie Dough Over Marshmallow Fluff to Make a Fluffernutter bar.

What is a Fluffernutter?

A fluffernutter is a simple sandwich made with peanut butter and marshmallows. During World War I, Emma Curtis published the sandwich, calling it a Liberty Sandwich. The name was changed to a fluffernutter sandwich in the 1960s for marketing purposes. Whatever it’s called, I am hooked on the combination of peanut butter and marshmallows.

How to Store

Fluffernutter Bars can be stored at room temperature or in the refrigerator in an airtight container. They will last up to three days.

Stack of 3 Fluffernutter Bars on a Counter Showing Inside Texture.

Can I Freeze Fluffernutter Bars?

Yes! These bars can be frozen for up to a month or two in a freezer-safe container. When storing the bars, separate the layers with wax paper or parchment. When ready to enjoy, let them thaw overnight in the refrigerator.

Fluffernutter Bars from Overhead Showing the Marshmallow that Spilled Up Over the Peanut Butter Bar.
5 from 1 vote

Fluffernutter Bars

Prep Time 10 minutes
Cook Time 40 minutes
Total Time 50 minutes
Fluffernutter Bars are peanut butter bars filled with a layer of marshmallow fluff.


  • 1 cup (258 g) creamy peanut butter
  • 1 cup (2 sticks / 226 g) unsalted butter, room temperature
  • 2 cups (400 g) light brown sugar, packed
  • 2 large eggs, room temperature
  • 2 teaspoons vanilla extract
  • 3 cups (375 g) all-purpose flour
  • 2 teaspoons cornstarch
  • 1 teaspoon kosher salt
  • 1 jar (7 ounces) marshmallow fluff


  • Preheat the oven to 350°F. Line an 9×13-inch baking dish with parchment paper.
  • In a large bowl, add peanut butter, butter, and brown sugar. Using a hand mixer, combine the mixture until smooth and creamy, about 2-3 minutes.
  • Scrape down the sides of the bowl. Add egg and vanilla and mix until combined (about 30 seconds).
  • Add in flour, cornstarch, and salt.
  • With the mixer on low, incorporate the ingredients until just combined (30 seconds-1 minute).
  • Spread about half of the dough into the bottom of the prepared baking dish.
  • Top the dough with the marshmallow fluff.
  • Using the remaining dough, form small discs and place them over the top of of the marshmallow fluff.
  • Bake for 35-40 minutes, or until golden.


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Meet Amanda Rettke

Amanda Rettke is the creator of I Am Baker, and the bestselling author of Surprise Inside Cakes: Amazing Cakes for Every Occasion – With a Little Something Extra Inside.Over the course of her 15+ year blogging adventure, she has been featured in and collaborated with the Food Network, New York Times, LA Times, Country Living Magazine, People Magazine, Epicurious, Brides, Romantic Homes, life:beautiful, Publishers Weekly, The Daily Mail, Star Tribune, The Globe and Mail, DailyCandy, YumSugar, The Knot, The Kitchn, and Parade, to name a few.

Reader Comments

  1. Hi Amanda, I want to make the Fluffernutter bars, but I am allergic to gelatin, What can I use in the recipie.?”

    1. I suppose you could use a vegan marshmallow fluff, but I have not tested that so don’t know how it will bake up.

  2. Hi, can these be made with gluten free flour? I’m a new to a gluten free diet and looking so I’m not sure how recipes translate with gluten free 1:1 flour. Thank you for your input!

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