Fluffernutter Brownies are creamy peanut butter and marshmallow fluff sandwiched and baked between two layers of the ultimate fudgy brownies. The brownie layers provide a rich, chocolaty flavor, while the peanut butter and marshmallow layers add a creamy and fluffy contrast! You will love my Fluffernutter Cookies, too!

Fluffernutter Brownies From Above Right Out of the Oven and Cut Into Squares.
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What is a Fluffernutter?

A fluffernutter is a simple sandwich made by spreading peanut butter on a slice of bread, then spreading the same amount of marshmallow creme on another slice, and combining them to form a sandwich. Its delicious flavor combination has inspired many of my latest desserts! After I made fluffernutter bars, I went on to make even more peanut butter marshmallow treats. Check out my fluffernutter rice krispie bars and fluffernutter fudge, too!

Steps for Making Fluffernutter Brownies With Brownie Batter, Peanut Butter, Fluff, and More Brownie Batter.

Ingredients & Substitutions

It all starts with my double fudge brownies in this recipe (which you have to try on their own, too)!

Cocoa Powder: I used regular unsweetened cocoa powder in the brownies. You could also use Dutch-processed cocoa powder if that is what you have. If using Dutch-processed, the brownies will have a darker color.

Butter: For fudgy brownies, a little less flour is used with lots of butter added to the batter. I added 2 sticks of butter to melt with the sugar! (Yes, that step is important.) For best results, use unsalted butter.

Espresso Powder: A teaspoon of espresso powder enhances and intensifies the chocolate flavor in the brownies. However, it will not give you a coffee taste. If you don’t have any on hand, you could leave it out. But, the brownies may not have as intense of a chocolate flavor.

Chocolate Chips: I used semi-sweet chocolate chips in the brownies.

Peanut Butter: For the creamy texture, I used creamy peanut butter. However, you could use the crunchy variety for a nutty texture.

Marshmallow Fluff: Marshmallow Fluff, also known as Marshmallow Creme, is not even made with marshmallows, but it has a similar flavor. It’s a paste perfect for sweet treats and desserts like these brownies.

Stack of Fluffernutter Brownies on a White Counter.

Can I Cut This Recipe In Half?

Sure! This does make a large pan of brownies, so go ahead and halve the recipe if preferred. Try half the recipe in an 8 or 9-inch square baking dish. You may need to adjust the baking time, so watch the brownies closely.

Fluffernutter Brownie on a White Plate.

How To Store Fluffernutter Brownies

When storing fluffernutter brownies, first, let them cool completely. Then, store them in an airtight container at room temperature. They will last up to 3 days.

Can I Freeze Fluffernutter Brownies?

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

More Fluffernutter Recipes

4.75 from 4 votes

Fluffernutter Brownies

Prep Time 20 minutes
Cook Time 28 minutes
Total Time 48 minutes
Fluffernutter Brownies are creamy peanut butter and marshmallow fluff sandwiched and baked between two layers of fudgy brownies.


  • 1 ⅓ cups (167.3 g) regular unsweetened cocoa powder
  • 1 cup (125 g) all-purpose flour
  • 1 teaspoon baking powder
  • ½ teaspoon kosher salt
  • 1 teaspoon espresso powder
  • 1 cup (2 sticks / 227 g) unsalted butter, room temperature
  • 2 cups (400 g) granulated sugar
  • 1 cup (168 g) semi-sweet chocolate chips
  • 1 tablespoon vanilla extract
  • 4 large eggs, room temperature
  • ¾ cup (193.5 g) creamy peanut butter
  • 1 cup (96 g) marshmallow fluff


  • Preheat the oven to 350°F. Line a 9×13-inch ceramic baking dish with parchment paper.
  • To a large bowl, add cocoa powder, flour, baking powder, salt, and espresso powder. Whisk to combine and set aside.
  • In a large saucepan over medium heat, add butter and sugar. After the butter has melted, heat to a low boil and cook for 2 more minutes, or until it reaches 230°F on an instant-read thermometer, stirring occasionally.
  • Remove from heat and stir in the chocolate chips and vanilla until completely melted. (The mixture might still be grainy.) Allow it to cool for about 10 minutes.
  • Add eggs, one at a time, stirring constantly until smooth.
  • Add the dry ingredients to the chocolate mixture and mix until just combined. The batter will be thick.


  • Spread half of the batter into the lined baking dish.
  • Spread the peanut butter over the batter. Then, using a piping bag or a plastic bag with the corner cut off, pipe the marshmallow fluff on top of the peanut butter.
  • Top with the remaining brownie batter.
  • Bake for 28-30 minutes.
  • Allow the brownies to cool completely before cutting and serving.


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What the Test Kitchen had to say about this recipe:


Get ready for a taste sensation like no other with these indulgent fluffernutter brownies! You get the combination of fudgy brownie, creamy peanut butter, and gooey marshmallow fluff in every mouthwatering bite!


Chocolate, peanut butter, AND marshmallow fluff?!? Seriously, what could be a better combination? If you have read my other reviews, you know I am all about fluffernutter treats (peanut butter and marshmallow), and this one is another winner!


Mmmmm. These brownies are one of a kind! I cannot resist these! The creamy, salty peanut butter and the fluffy marshmallow go with the flavor of the brownie so perfectly. You have to try these!

A perfect combo sure to make you smile! We worked on this on for awhile, and the end result is perfection!!!!


Chocolate, peanut butter and marshmallow meet in a perfect brownie. The brownie texture is fudgy and perfect and the salty peanut butter contrasts so nicely with the sweet fluff and chocolate!

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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. Great recipe but the marshmallow fluff was really hard to get into the bag and onto the brownies! I laughed at myself when I ended up with it all over my hands 😂. What better combination?

    1. You can place the bag in a glass with the open end at the top. Spoon fluff into the bag. Seal bag, cut off tip. Then pipe.

  2. OMG, this sounds so delicious and I want to try it like asap, tomorrow! I just love all the ingredients that are in it. I have a graduation coming up in a couple weeks but maybe I should just try it on my husband first and see how it turns out, then fix it for the graduation or a kids fishing tournament coming up! Thank you so much!! 😋

  3. This was an amazing test – and you got all “A’s” in my cookbook! They were super easy to make and didn’t take much time to put together. I must say I was a bit skeptical, but the finished product proved me wrong. Thank you for sharing such an awesome recipe!

      1. Thank you! I appreciate your time answering my question. Also love your recipes. Used several for Christmas baking with 3 of my grands.

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