Fluffernutter Cake.

Rich and moist peanut butter cake topped with marshmallow frosting and peanut butter cups. It’s like biting into a fluffernutter sandwich, but better!

Rich and moist peanut butter cake topped with creamy marshmallow fluff frosting and peanut butter cups!

What is a Fluffernutter, you ask?

A fluffernutter is a peanut butter + marshmallow creme sandwich. My older sister Sarah loved them when we were growing up!   The term fluffernutter can also describe desserts combining the tastes of peanut butter and marshmallow. And did you know? The Fluffernutter is the official sandwich of Massachusetts. They sure know what they’re doing up there!

Rich and moist peanut butter cake topped with creamy marshmallow fluff frosting and peanut butter cups!

I had leftover Fluff (marshmallow creme) from making my S’mores Cookie Bars (must make!). I brainstormed for a minute and decided to use the rest of the XXL jar for frosting. A quick marshmallow frosting to pair with a super-moist, dangerously good peanut butter cake.

The peanut butter cake is the same batter I use for my super-moist, super peanut buttery Peanut Butter Cupcakes. This is my go-to peanut butter cupcake. It’s not made with white sugar – all brown sugar, baby. The brown sugar and the eggs are why it is so darn moist!

I find that many peanut butter cupcakes and peanut butter cake recipes lack flavor. They tend to have a dry texture and not nearly enough peanut butter taste. My peanut butter cake and cupcake recipe is the complete opposite. It’s like biting into pure peanut butter.

The best part?  The peanut butter cake is so easy to make!

Fluffernutter Cake - a moist, rich peanut butter cake topped with a creamy marshmallow frosting and decorated with peanut butter cups. So easy to make! sallysbakingaddiction.com

Doesn’t the frosting look like a cloud? So good. Creamy marshmallow sitting atop a moist peanut butter cake. Fluffernutter at its finest.

Rich and moist peanut butter cake topped with creamy marshmallow fluff frosting and peanut butter cups!

I spread the frosting on the cake with a knife. Nothing fancy. I opted out of frosting the sides of the cake because it is SO much easier to just frost the top.  Save yourself the time. Depending on how thick you slather the frosting onto the cake, you may have leftovers.

Leftover frosting is a wonderful accompaniment to graham crackers. Just sayin’.

Fluffernutter Cake-2

Reese’s Peanut Butter Cups are the decor of choice for the cake. Because… why not?  Chop up 8 full size Reese’s Cups and sprinkle around the edges. Or all over – whatever you prefer. Decorating the cake is almost as fun as eating it. (Almost.)

Like banana bread and carrot cake, I find that peanut butter cake tastes best on day 2 after the flavors have settled and have gotten friendly with one another. It is also more moist on the 2nd day as well.  This didn’t stop us from digging right in after the photoshoot though!

It’s a one layer cake, which is much more practical for Kevin and I.  A couple leftover slices can easily be given away to friends and neighbors.  Double layer cakes and sheet cakes are my answer to birthdays and parties, but a simple cake like this can be made for any occasion. If you’d like to make this a double layer cake, simply double all of the ingredients and bake in two 9-inch round pans.

Rich and moist peanut butter cake topped with creamy marshmallow fluff frosting and peanut butter cups!

So there you have it… a twist on the classic Fluffernutter sandwich we remember as kids. It’s simply the best peanut butter cake I’ve ever eaten.  I was blown away by its flavor and just how easy it was to make.  There is no excuse not to try this if you’re a Fluffernutter Lover. 😉

Follow me on Instagram and tag #sallysbakingaddiction so I can see all the SBA recipes you make. 

Fluffernutter Cake

Rich and moist peanut butter cake topped with marshmallow frosting and peanut butter cups. It's like biting into a fluffernutter sandwich, but better!

Yield: 1 cake, serves 10

Ingredients:

Cake

  • 1/2 cup (1 stick or 115g) unsalted butter, softened to room temperature
  • 3/4 cup (150g) packed dark brown sugar
  • 2 large eggs
  • 2/3 cup (170g) creamy peanut butter
  • 1 teaspoon vanilla extract
  • 1 and 1/4 cups (160g) all-purpose flour (careful not to overmeasure)
  • 1 teaspoon baking powder
  • 1/4 teaspoon salt
  • 1/4 cup buttermilk*

Marshmallow Frosting

  • 7.5 oz (1 cup; 213g) container marshmallow creme (Fluff)
  • 8 oz (225g) cream cheese, softened to room temperature*
  • 1/2 cup (60g) confectioners' sugar
  • 2 teaspoons vanilla extract
  • 1/2 teaspoon salt
  • 8 Reese's Peanut Butter Cups, chopped (optional)

Directions:

Preheat oven to 350F degrees. Spray a 9x2 inch cake pan (or 9-inch springform pan) with nonstick spray. Set aside.

Make the cake: Using a handheld or stand mixer, beat the butter and brown sugar together on medium speed in a large bowl until creamed. About 2-3 minutes. Add eggs, one at a time, and beat until combined. Scrape down the sides of the bowl as needed. Add the peanut butter and vanilla extract, beating for about 2 full minutes. Set aside.

In a medium sized bowl, toss together the flour, baking powder, and salt. Slowly add the dry ingredients to the wet ingredients in 3 additions, stirring by hand after each addition. Batter will be thick. Add the buttermilk and mix until just combined, do not overmix.

Spoon the batter into the prepared cake pan. Bake for 20 minutes. Remove from the oven and loosely cover with aluminum foil. Bake for an additional 12-13 minutes or until a toothpick inserted in the center comes out clean. Allow cake to cool completely in the pan on a wire rack.

Make the frosting*: In a medium sized bowl, beat the cream cheese on medium-high speed until smooth and creamy. Turn off the mixer, add the marshmallow creme and beat on low speed for 1 minute. Slowly add the powdered sugar and vanilla extract and beat for 1 minute. Add the salt and continue to beat. Add more powdered sugar if you'd like the frosting to be thicker. Add more salt to cut that extra sweetness.

Remove the cake from the pan by inverting it onto a large plate or cake stand. Frost the cake as desired. There will be leftover frosting depending how much frosting you use. Decorate with chopped Reese's Cups. Cake stays fresh (covered) at room temperature or in the refrigerator for 4 days.  Frost immediately before serving.

 

 

Recipe Notes:

*Please use buttermilk to obtain the moistest texture.

*If you are not a fan of cream cheese, I suggest making this marshmallow frosting instead (it is what I use to fill my marshmallow s'more cupcakes).

*If you'd like to make this a double layer cake, simply double all of the ingredients and bake in two 9-inch round pans.

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© Sally’s Baking Addiction. All images & content are copyright protected. Please do not use my images without prior permission. If you want to republish this recipe, please re-write the recipe in your own words, or link back to this post for the recipe.

 

If you love marshmallow, you have to try my S’mores Cookie Bars.

It’s like bringing the campfire inside. 😉

S'more Cookie Bars

 

Today’s cake recipe is the same batter that I use for my Peanut Butter Cupcakes with Dark Chocolate Frosting.

Peanut Butter Cupcakes with Dark Chocolate Frosting

 

 

So, have you ever had a fluffernutter sandwich?

Rich and moist peanut butter cake topped with creamy marshmallow fluff frosting and peanut butter cups!

 

 

 

125 comments

  1. Can it be my birthday again so I can have this?

  2. Though I never ate fluffernutter sandwiches, pb and marshmallow is one of my favorite flavor combos now. I actually had a homemade pb cookie with homemade marshmallow on top tonight. I also love pb cake and this looks awesome!

  3. Holy moly! This cake is fantastic, it looks pretty dangerous 😉

  4. I think I may have found Mr. L’s birthday cake. Only I might put banana slices on top and make it an Elvis cake!

  5. Hi Sally, this cake looks AMAZING! (fellow peanut butter lover) just wondering, would it be possible to leave out the marshmallow topping if you’re not a fan? or would it be a bit bland iwthout it? 🙂

    • Yes, you could leave the frosting off of the cake if you’d like. Maybe add 1/2 cup chocolate chips to the cake to add a little “something” to the peanut butter cake? Enjoy!

  6. Haii Sallly,

    I was just wondering if, if needed how much buttermilk should I add to the recipe?

  7. Hi, i made this fluffernuttercake for my friend who is a big america-fan and it was such a success! thank u so much for the recipe and already converting the measurments! That was really helpfull. I was afraid that the frosting would be too sweet but it was just right!

    Thank u!

    Elodie from Belgium.

  8. Hi don’t know if you have been asked this already, would it change the taste to use light brown sugar instead of the dark brown sugar?

  9. This looks SO good since I am a huge Fluffernutter sandwich kid from way back when!! I grew up in upstate NY so Fluff was THE marshmallow creme. I now live in central Texas and just introduced my three children to the real Fluff and they are hooked.

    I MUST make this dessert for someone…not sure yet, but someone! I am a new subscriber to your website and so far, I am so impressed by what I have seen.

    I will report back after making this delicious looking dessert.

    Thank you! 🙂

    • Thanks so much Kathryn! For both subscribing to my blog and for loving this cake recipe. Fluff is totally THE one and only marshmallow creme!

  10. Just got your cookbook for Mother’s day (beyond excited!), and I made the peanut butter cake from that. We found it quite dry just wondering if this is the “updated” version of the recipe and if I’d have better luck with this one. The only thing I did differently was use light brown sugar instead of dark maybe that was the problem?

    • Hey Claire! This is the same recipe, only calling for buttermilk and an extra Tablespoon of it – I find it adds to the moist texture. So sorry you found the PB cake dry. How about using this buttermilk option?

  11. Sally,
    I am making this plus your peanut butter stuffed brownies for my niece’s grad party this weekend — what, if anythng, can be made ahead? Do you think they’d keep overnight? out or in the fridge?

    thank you!

    Also making your pineapple upside down cake for everyone that is coming in to town Friday — am so excited hitting the gym as much as possible so I can enjoy!! ; )

  12. I was so excited to try this recipe that I ran out and bought the ingredients this morning. I followed the recipe to the absolute letter, measuring super carefully, but my results were disappointing to say the least. The cake is fine, the icing however is not good. It is runny and would not thicken up no matter how much powdered sugar I added. And the cream cheese taste is incredibly overwhelming. Not anything at all like marshmallow fluff. I despise cream cheese flavor and was trusting the comment that it would taste nothing like cream cheese or I would not have even tried the recipe. If you hate cream cheese flavor, this is not the recipe for you. So sad because it sounded so delicious.

  13. I made this cake yesterday, and it was beautiful. The frosting was wonderful. The only downside was that the cake was very dry. I think that the baking time may have been a bit long for down south (used 9″ springform). I split the cake horizontally and essentially made two layers and put frosting in the middle – then covered and refridgerated overnight, which helped. I would definitely make this again, and cut the baking time.
    FYI – I thought the icing seemed familiar, and it is the same recipe that a friend uses for the best fruit dip ever. Amazing with strawberries!

  14. I have tried several of your recipes and have loved them all which is why I feel that I should let you know that I was disappointed in this one 🙁 I made the peanut butter cake for my birthday, but made it with a Nutella mouse filling and your Nutella frosting (Amazing). The cake itself was rather dry and did not have a great texture. The flavor was very peanut buttery and good but I did not enjoy the texture. I did make the cake with the buttermilk and followed all other ingredients and instructions as written.

  15. Hello, does anyone know the baking time for a 9*13 pan? I would like to make this for the holiday but I will need to double the recipe and would like to use a 9*13 pan instead of two rounds?

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