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Elizabeth Poett's Mocha Whoopie Pies with Peanut Butter Filling

Mocha Whoopie Pies with Peanut Butter Filling

byElizabeth Poett
Total 2 hours (includes chilling)
Active 60 mins
Makes 12 whoopie pies
Whoopie pies bring nothing but smiles, not only because it's fun to say the name, but also because they’re just so very good. Imagine two little cookie-sized cakes held together with a thick layer of delicious frosting and you have the essence of this dessert. Mocha cakes and peanut butter frosting in this version make for a scrumptious combination of flavors in every bite.
TIP: The batter will spread a bit as it bakes, so it’s important to space the cakes at least 3 inches apart on the baking sheets.
Special Equipment
a piping bag fitted with a large open star tip
Special Equipment
a piping bag fitted with a large open star tip
Ingredients
For the cakes
  • 2 cups all-purpose flour
  • 1/2 cup unsweetened cocoa powder
  • 2 tablespoons espresso powder
  • 1 teaspoon baking powder
  • 1 teaspoon baking soda
  • 1/2 teaspoon kosher salt
  • 1 cup whole milk
  • 1 teaspoon vanilla extract
  • 1 cup vegetable shortening
  • 1 cup packed dark brown sugar
  • 1 large egg, at room temperature
For the filling
  • 1 cup (2 sticks) unsalted butter, at room temperature
  • 1 cup unsalted creamy peanut butter
  • 4 cups powdered sugar, measured then sifted
  • 1 teaspoon kosher salt
  • 4 large egg whites, at room temperature
    Directions
    1. Preheat the oven to 350°F. Line 2 baking sheets with parchment paper and set aside.
    2. For the cakes: In a large bowl, sift together the flour, cocoa powder, espresso powder, baking powder, baking soda, and salt. Set aside. Place the milk in a liquid measuring cup, add the vanilla extract, and set aside.
    3. In the bowl of a stand mixer fitted with a paddle attachment, combine the shortening and brown sugar. Cream for 1 minute on medium speed. Add the egg and continue to beat on medium speed for another minute. Use a rubber spatula to scrape down the sides and bottom of the bowl, then beat again to ensure that the mixture is fully combined.
    4. Turn the speed to low. Add half of the flour mixture to the mixer. Add half of the milk mixture and continue to mix on low speed. When just combined, add the remaining flour mixture, followed by the remaining milk mixture, mixing for 3 minutes. The batter should be smooth and uniform in color.
    5. Use a large cookie scoop to scoop up equal amounts of cake batter and place on the prepared baking sheets, spacing them at least 3 inches apart (see Cook’s Note). Bake 12 to 15 minutes, or until the cakes spring back completely when lightly touched. Remove the pans from the oven. Use a metal spatula to transfer the cakes to a cooling rack and cool completely.
    6. For the filling: In the bowl of a stand mixer fitted with a paddle attachment, combine the butter and peanut butter and beat on medium speed until fully combined. Add the powdered sugar and salt to the bowl and beat on medium speed for about 3 minutes.
    7. Beat the egg whites in a separate bowl (use a whisk or a hand mixer) until the whites hold a stiff peak. Add the egg whites to the bowl of the stand mixer and beat the mixture until it is light and fluffy. This should take 3 to 5 minutes. Transfer the mixture to a piping bag fitted with a large open star tip.
    8. To assemble the pies, pipe a generous amount (2 to 3 tablespoons) of filling onto the flat side of one cooled cake, then cover with the flat side of a second cake to make a sandwich. Repeat with each pair of cakes. Cover with plastic wrap, making sure the plastic is airtight. Refrigerate for at least an hour and up to overnight to firm the filling before serving.
      Consumption of raw or undercooked eggs, shellfish and meat may increase the risk of foodborne illness.