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

Print Recipe

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



  • 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)


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.

Additional 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.



© 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!





124 Responses to “Fluffernutter Cake.”

  1. #
    Amyposted June 26, 2013 at 10:32 pm

    I never like frosting the sides of the cake! I rarely ever get it to look even and pretty… So I love just spreading the frosting on top of the cake too. And cream cheese marshmallow frosting… I am SO in love. I’d definitely put the extra on some graham crackers (or extra Reese’s cups)!


  2. #
    Julie @ Table for Twoposted June 26, 2013 at 10:37 pm

    Must have this soon!!


  3. #
    Deborahposted June 27, 2013 at 12:08 am

    This cake looks like a little bit of heaven, Sally!


  4. #
    angela @ another bite pleaseposted June 27, 2013 at 8:33 am

    oh gosh when i saw this on instagram i was like oh my! this looks crazy good. crazy.


  5. #
    Katieposted June 27, 2013 at 10:55 am

    I have to have a slice of this cake – it sounds incredible!


    • Sallyreplied on June 27th, 2013 at 11:54 am

      Thanks Katie!


  6. #
    laurasmessposted June 27, 2013 at 11:28 am

    Oh my. Sally, this looks like absolute heaven on a plate. I’ve never heard of a fluffernutter but as soon as I saw the moist, gooey peanut butter interior, I was sold! I love pb. Particularly with chocolate. I might even try your dark chocolate frosting recipe on this cake so that I can eat a giant pb and chocolate cake (we can’t really buy Reese’s pb cups here in Australia so making the cake like a giant one is the next best thing!) x


    • Sallyreplied on June 27th, 2013 at 11:54 am

      You can’t go wrong with peanut butter and chocolate – ever! Thanks Laura!


  7. #
    Denny Felizziposted June 27, 2013 at 4:17 pm

    I will be 57 years old on 6/28/13
    I STILL eat Fluffernutter ‘s. Yes my wife thinks i’m strange. But they are something memorable from my childhood. And i really like them :)


    • Sallyreplied on June 27th, 2013 at 4:33 pm

      Happy early birthday! And that is amazing about the fluffernutters. :)


  8. #
    Megan @ For the Love of Cookiesposted June 27, 2013 at 5:52 pm

    I remember eating pb & fluff sandwiches when I was little. My cousins introduced the idea to me and I loved it! I haven’t had one in years! And that peanut butter cake. Seriously. It looks so good and moist. I’ve never had pb cake (yet!) but I feel like it could be hard to get the right texture – but you most certainly nailed it! Love this!


    • Sallyreplied on June 27th, 2013 at 7:26 pm

      Thanks Megan! And yes – hard to nail down that “perfect” peanut butter cake texture. This is so moist!


  9. #
    Ari @ Ari's Menuposted June 28, 2013 at 12:43 pm

    Oh girl, you had me at fluffernutter!!! This looks amazing!!! I agree that peanut butter cakes often come out dense and dry, so I LOVE that you’ve come up with a recipe that combats that and still has tons of pb flavor!


    • Sallyreplied on June 28th, 2013 at 7:14 pm

      Thanks Ari – and you just have to try it!


  10. #
    Rachel (teacher-chef)posted July 1, 2013 at 7:54 am

    I LOVE this! Although my Fiance thinks Peanut Butter is overused in our kitchen (silly boy),my Flower Girl LOVES fluffernutter sandwiches… will be making this for her this week!


    • Sallyreplied on July 1st, 2013 at 10:01 am

      Silly boy, indeed! There is never enough PB. Thanks Rachel – hope she enjoys!


  11. #
    Erin @ The Spiffy Cookieposted July 2, 2013 at 12:00 pm

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


    • Sallyreplied on July 2nd, 2013 at 12:02 pm

      You don’t need to be the birthday girl to have this Erin!


  12. #
    Laura Dembowskiposted July 3, 2013 at 9:11 pm

    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!


    • Sallyreplied on July 4th, 2013 at 8:07 am

      homemade pb cookie + homemade marshmallow. that sounds like a dream!


  13. #
    Nutmeg Nannyposted July 10, 2013 at 12:36 pm

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


  14. #
    Rae Lovvornposted August 22, 2013 at 7:48 pm

    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!


    • Sallyreplied on August 22nd, 2013 at 8:50 pm

      mmm that’s a great combination, Rae!


  15. #
    Janeposted November 24, 2013 at 3:31 pm

    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? :)


    • Sallyreplied on November 24th, 2013 at 3:50 pm

      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!


  16. #
    Laurynposted January 25, 2014 at 2:06 am

    Haii Sallly,

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


    • Sallyreplied on January 26th, 2014 at 7:25 am

      Sometimes I use 1/4 cup of buttermilk instead of the 3 Tbsp regular milk.


  17. #
    Elodieposted March 2, 2014 at 11:34 am

    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.


  18. #
    Savannaposted March 27, 2014 at 8:16 pm

    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?


    • Sallyreplied on March 27th, 2014 at 8:37 pm

      light brown sugar would be just fine


      • Savannareplied on March 27th, 2014 at 8:41 pm

        Thank you!

  19. #
    Kathryn Cothernposted March 31, 2014 at 1:15 pm

    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! :)


    • Sallyreplied on March 31st, 2014 at 1:25 pm

      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!


  20. #
    Claireposted May 11, 2014 at 8:06 pm

    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?


    • Sallyreplied on May 12th, 2014 at 8:56 am

      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?


  21. #
    Michelleposted May 20, 2014 at 9:28 pm

    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!! ; )


  22. #
    Ginaposted June 25, 2014 at 6:46 pm

    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.


    • Sallyreplied on June 25th, 2014 at 7:34 pm

      Sorry you did not enjoy my recipe, Gina! Perhaps my other marshmallow filling/frosting will be tastier for you. Feel free to give it a try if you’d like. There is no cream cheese in this recipe. http://sallysbakingaddiction.com/2014/05/22/marshmallow-filled-smores-cupcakes/


      • Ginareplied on June 25th, 2014 at 7:36 pm

        I will definitely give it a try! Thanks! :)

  23. #
    Lea Annposted July 11, 2014 at 10:20 am

    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!


  24. #
    Traceyposted January 31, 2015 at 10:19 pm

    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.


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