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fluffernutter cupcakes
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Peanut butter cupcakes with marshmallow frosting

A peanut butter cupcake filled with a no bake peanut butter mousse filling and topped with a toasted marshmallow frosting!
Prep Time1 hr
Cook Time22 mins
Total Time1 hr 22 mins
Course: Dessert
Cuisine: cupcakes
Servings: 30 cupcakes


For The Cupcakes

  • 3 cups cake flour
  • 1 tbsp. baking powder
  • ½ tsp. salt
  • 16 tbsp. unsalted butter at room temperature
  • 2 cups sugar
  • 5 large eggs at room temperature
  • 1/2 cup peanut butter
  • cups buttermilk at room temperature
  • 2 tbsp. vanilla extract

For the peanut butter filling

  • 1 cup confectioner sugar
  • 4 ounces softened cream cheese
  • 1/2 cup peanut butter
  • 1 teaspoon vanilla
  • 1 Tablespoon milk

For the Marshmallow Frosting

  • 1 1/2 cup granulated sugar
  • 1/3 cup cold water
  • 2 egg whites
  • 1/4 teaspoon cream of tartar
  • pinch of salt
  • 1 1/2 teaspoon vanilla
  • 1 tbsp corn syrup


For the Cupcakes

  • In a medium mixing bowl, combine the cake flour, baking powder and salt. Whisk together and set aside.
  • Add the butter to the bowl of an electric mixer fitted with the paddle attachment. Beat on medium-high speed for 3 minutes, until light and creamy in color. Scrape down the sides of the bowl and beat for one more minute.
  • Add the sugar to the butter mixture, ¼ cup at a time, beating 1 minute after each addition. Mix in the eggs one at a time until incorporated. Add in your peanut butter and mix to combine. Scrape down the sides of the bowl after each addition. Combine the buttermilk and the vanilla extract in a liquid measuring cup. With the mixer on low speed, add the dry ingredients alternately with the wet ingredients, beginning and ending with the dry ingredients and mixing just until incorporated. Scrape down the sides of the bowl and mix for 15 seconds longer.
  • Divide the batter between the prepared paper liners, filling each about 2/3 of the way full (you will likely have batter left over after filling 24 wells.I managed to make a full 3 dozen cupcakes) Bake 18-22 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool in the pans 5-10 minutes, then transfer to a cooling rack to cool completely.

For the peanut butter filling

  • In a stand mixer bowl, using your paddle attachment combine all ingredients and mix to combine. You can also do this with a hand mixer in a mixing bowl as well. If all you have is a whisk, make sure your ingredients are room temperature and use those muscles! Keep refrigerated until ready to use! Once your cupcakes are cooled, remove the center and fill with the peanut butter mousse.

For the frosting

  • Combine the egg whites, sugar, water, and corn syrup in a large stainless steel bowl or any other heatproof bowl. Use an electric handheld mixer to beat the ingredients together until well combined. Place the bowl over a saucepan of simmering water. Continue to beat on medium-low speed for 3 minutes. Turn the speed up to high and beat for 3-4 minutes or until soft peaks begin to form.
  • Remove from heat, add the vanilla extract, and continue beating on high until the frosting is thick and spreadable, about 1-2 minutes. Cool to room temperature and use immediately. Pipe onto your cupcakes with a piping bag and pastry tip (I used a French star tip, but any tip will do.) Then lightly torch the frosting with a kitchen torch. Alternately, you could place them in your oven (put them on a cookie sheet, and no closer than middle rack) and set to broil but keep a really close eye one them otherwise they will burn!


  • Make sure to measure your flour correctly by scooping and leveling. Here is a tutorial on how to measure your flour correctly.
  • This recipe uses cake flour which helps to create a light and fluffy cupcake. If you use all purpose flour it will change the texture a bit. You can also make your own cake flour.
  • Make sure your eggs, buttermilk, and butter are at room temperature.
  • The recipe calls for buttermilk. Do not substitute regular milk because it will alter the balance of the ingredients due to the acidity in the milk.  You can also make your own cake flour
  • Do not use an all natural peanut butter, it contains too much oil.