My whoopie pie recipe has a sweet marshmallow filling sandwiched between rich chocolate cake for a classic New England dessert - but without the shortening! Ready in less than 30 minutes, and perfectly paired with a cold glass of milk, a White Chocolate Mocha, or a Honey Vanilla Latte.
Preheat oven to 350ºF and line two baking sheets with nonstick silicone mats or parchment paper. Set aside.
In the bowl of a stand mixer, combine butter and brown sugar and whip on high speed until light and fluffy.
1/2 cup unsalted butter, 1 1/4 cup light brown sugar
Add egg and vanilla, and beat to combine.
1 egg, 1 teaspoon pure vanilla extract
In a separate large mixing bowl, combine flour, cocoa powder, baking soda, espresso powder and salt, and whisk to combine.
2 cups all-purpose flour, 1/2 cup cocoa powder, 1 1/4 teaspoons baking soda, 1/2 teaspoon espresso powder, Large pinch of salt
With the mixer on a low speed, add the dry ingredients to the wet ingredients, alternating with the buttermilk until just combined.
1 cup buttermilk
Use a medium cookie scoop to portion dough onto prepare baking sheets. You want to make sure you're leaving enough room (about 2") between each cake so they can spread. I wouldn't do more than 5 on a baking sheet at a time, just to be safe.
Bake for 9-11 minutes, or until the tops spring back when touched.
Let cool on baking sheets for 5 minutes, then move to wire racks to cool completely.
Filling
In a large bowl, combine marshmallow Fluff and butter and beat on high speed until well combined and smooth.
1 cup marshmallow Fluff, 1/2 cup unsalted butter
Add 1 cup of the powdered sugar, vanilla extract and heavy cream and beat until well combined. If it's too thin, add more of the powdered sugar a little at a time until you have the desired consistency.
1 - 1 1/2 cups confectioners’ sugar (powdered sugar), 1 teaspoon pure vanilla extract, 1 tablespoon heavy cream
If you feel it's too sweet for your tastes, add a pinch of salt.
Assembling
Start by flipping half of the cooled cakes over and matching them up by size with another half that will go on top.
Fill a pastry bag with the tip cut off (or plastic sandwich bag) with filling and pipe it onto each cake half in a spiral shape. Leave about 1/4" around the edge so that when you add the other cake half on top, the filling has a little room to spread.
Top each with the other cake half. Serve and enjoy!
Video
Notes
Equipment: You don't need a fancy whoopie pie pan to make the chocolate cakes! Just use a standard baking sheet lined with nonstick silicon mats or parchment paper.
Batter: The batter should be firm enough to be scooped, because a liquidy batter won't be able to hold its structure to bake, or to support the filling. I like to use a medium cookie scoop to portion the batter.
Cooling: Make sure you let the cakes cool completely before you sandwich them with the filling, otherwise they'll be tacky and difficult to work with.
Storage: Wrap each whoopie pie in plastic wrap and then place in an airtight container in the fridge for up to 1 week.