Instructions

• Position a rack in the center of the oven and preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper and set them aside.
• In a medium bowl, whisk together the 3 cups all-purpose flour, 1/3 cup unsweetened cocoa powder, 1 teaspoon baking powder, 1/2 teaspoon baking soda, and 1/2 teaspoon salt. Set the dry mixture aside.
• In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), combine 1/2 cup unsalted butter (room temperature), 1/2 cup vegetable shortening, 1/2 cup light brown sugar, and 1 cup granulated sugar. Beat on low just to combine, then increase to medium and beat until the mixture is light and fluffy, about 4–5 minutes.
• Add the 2 eggs one at a time, beating well after each addition. Add 2 teaspoons vanilla extract and 3 teaspoons red food coloring and beat on low until just blended.
• With the mixer on low speed, add half of the dry flour mixture, then add half of the 1 cup buttermilk. Mix just until the ingredients are incorporated. Scrape down the sides and bottom of the bowl with a spatula.
• Add the remaining half of the dry flour mixture and the remaining half of the buttermilk. Mix on low until the batter is completely combined and smooth, taking care not to overmix.
• Using a tablespoon or a medium cookie scoop, drop portions of batter onto a prepared baking sheet, spacing them at least 2 inches apart. (Work on one sheet at a time if you prefer to bake individually.)
• Bake one sheet at a time on the center rack for about 10 minutes, or until the cake rounds spring back lightly when pressed in the center. Remove the sheet from the oven and let the cake rounds rest on the sheet for 5 minutes, then use a spatula to transfer them to a wire rack to cool completely. Repeat with the second sheet.
• While the cakes cool, make the cream cheese filling. In the bowl of a stand mixer with the paddle attachment (or using a hand mixer), beat 4 ounces cream cheese (room temperature) and 1/4 cup unsalted butter (room temperature) on medium speed until smooth.
• With the mixer on low, gradually add 3 1/2 cups powdered sugar until combined. Add 1 teaspoon vanilla extract, then increase the speed to medium-high and beat until the filling is creamy and smooth, about 3–4 minutes. Scrape the bowl as needed.
• Assemble the whoopie pies by spreading or piping the filling onto the flat side of one cooled cake round, then topping with a second cake round, flat-side down, to form a sandwich. Repeat until all cakes and filling are used.
• Store assembled whoopie pies in an airtight container at room temperature for up to 3 days. If you need to stack them, place a piece of wax paper between layers.