Wow. This cupcake is all sorts of amazing. It is a banana cupcake + whipped peanut butter filling + fluffy marshmallow frosting. It sounds like it might be either delicious or gross, and I’m here to tell you that it is 100% delicious. Seriously.
Stephen celebrated his birthday last week and we had a fun weekend in Vermont to celebrate. We ate a great meal (and sat at what is apparently one of the most romantic tables in the country) , tasted some maple syrup, ate a bunch of cheese, visited a brewery (that one was purely for the birthday boy), and spent 2 hours at the King Arthur Flour store (really cool!). Is there anything better than Vermont? I kind of don’t think so. What we didn’t have was a birthday dessert. And every birthday deserves a birthday dessert. So we corrected that oversight this weekend with this supremely wonderful dessert.
This cupcake combines Elvis’s favorite combo of peanut butter and banana and the classic fluff and peanut butter or “fluffernutter” combo. It seems like it shouldn’t work. But it SO does.
This is a fairly straightforward recipe, but it’s helpful to split up the work. I made the cupcakes at night and then filled and frosted them in the morning. The banana cupcake is very similar to banana bread, but less dense. The marshmallow frosting is light, fluffy, and deliciously creamy. But the peanut butter filling is to die for! I’m pretty sure I could just eat spoonfuls of this stuff (so could this guy). The flavors and textures combine to create a rich, creamy, deliciously wonderful cupcake. Imagine a fluffernutter on banana bread but so much better. It’s a cupcake fit for the King.
- 2 ¾ cups all-purpose flour
- 1 ¼ teaspoon baking powder
- 1 teaspoon baking soda
- ½ teaspoon salt
- 4 ounces unsalted butter at room temperature
- ¼ cup vegetable shortening at room temperature (use butter if you don’t have shortening)
- 1 ¾ cups granulated sugar
- 2 teaspoons vanilla extract
- 2 eggs
- 1 ½ cups mashed very ripe bananas (about 4 bananas)
- ½ cup buttermilk
For the peanut butter filling:
- 1 cup confectioners’ sugar
- 1 cup creamy peanut butter
- 5 tablespoons unsalted butter at room temperature
- ¾ teaspoon vanilla extract
- ¼ teaspoon kosher salt
- ⅓ cup heavy cream
For the marshmallow frosting:
- 4 large egg whites, at room temperature
- 1 cups granulated sugar
- ¼ teaspoon cream of tartar
- Pinch of fine salt
- 1 teaspoon vanilla extract
For the banana cupcakes
- Preheat the oven to 325 F. Line two cupcake pans with paper liners.
- Add the flour, baking powder, baking soda, and salt to large bowl. Whisk ingredients together and set aside.
- In the bowl of an electric mixer fitted with the paddle attachment, beat the butter and shortening together on medium speed until light and creamy, about 3 minutes.
- Add the sugar and vanilla and beat on medium speed until fluffy, about 3 minutes.
- Scrape down the sides of the bowl, add the eggs, and beat until just combined.
Scrape the bowl again and add the mashed bananas. Beat until just combined.
- With the mixer on low, add the flour mixture, alternating with the buttermilk, in three additions. Begin and end with the flour mixture. Scrape down the sides, then mix on low speed for a few seconds.
- Fill the cupcake liners three-fourths full and bake for 20-25 minutes, or until a tooth inserted in the center of a cupcake comes out clean. Be sure to rotate the pans after 10 minutes.
- Remove the cupcakes from the pan and let cool on a rack before filling.
To make the peanut butter filling:
- Add the confectioners’ sugar, peanut butter, butter, vanilla, and salt to a bowl (you can use a standing mixer or a regular electric mixer).
- Beat on low speed until sugar is combined, and then increase to medium for 1-2 minutes.
- Add the heavy cream and mix on medium-high speed until filling is light and fluffy
To make the marshmallow frosting:
- Fill a medium saucepan with 1 inch of water and bring to a simmer over medium heat.
- Meanwhile, add the egg whites, sugar, cream of tarter, and salt to the bowl of a standing mixer and whisk by hand until well combined.
- Once the water is simmering, place the bowl over the saucepan, making sure the bowl is not touching the water. Whisk constantly and heat the mixture until the sugar has dissolved and mixture is 160 F on an instant-read or candy thermometer- about 6-8 minutes.
- Remove the bowl from the saucepan and transfer to a standing mixer. Mix on high speed using the whisk attachment until the frosting has stiff, glossy peaks, about 6 minutes.
- Add the vanilla and mix on high speed for 1 more minute. Scrape the bowl if necessary to incorporate the vanilla.
To assemble the cupcakes:
- Use a small paring knife to cut a cone out of the center of each cupcake*. These will taste better with a large amount of peanut butter filling, so don’t be afraid to cut out a fairly large cone. Fill with the peanut butter filling. Slice off the top of each cone and place on top of the filling. This is what it will look like with the filling:
- Frost with the marshmallow frosting and you’re done!
If you wish, use a kitchen torch to lightly brown the frosting.