For the Cakes:
2¼ cups all-purpose flour
1½ teaspoons baking powder
½ teaspoon salt
4 tablespoons unsalted butter, at room temperature
4 tablespoons vegetable shortening
½ cup sugar
½ cup packed brown sugar
2 large eggs
½ cup buttermilk
2 tablespoons milk
1 teaspoon baking soda
1 teaspoon white vinegar
½ teaspoon vanilla
1 cup mini chocolate chips
For the Filling:
1¼ cups heavy cream
4 tablespoons confectioners’ sugar
3 tablespoons strawberry jelly
1 cup sliced strawberries
Preheat the oven to 375 degrees F. Line 2 baking sheets with parchment paper.
In a small bowl, sift together the flour, baking powder and salt. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, shortening, sugar and brown sugar until light and creamy, about 3 minutes. Add the eggs and the buttermilk and beat until combined.
In a measuring cup, combine the milk, baking soda and vinegar. Add the milk mixture to the batter along with the sifted flour mixture and beat on low speed until just combined. Add the vanilla then beat on medium speed for about 2 minutes, or until completely combined. Fold in the mini chocolate chips.
Using a spoon, drop about 1 tablespoon of batter at a time onto the baking sheets. Space them at least 2 inches apart. If you want heart shaped whoopie pies, use a small heart shaped cookie cutter to form a heart shape then carefully pull the cutter away leaving the batter in a heart shape. Or use a whoopie pie pan with heart molds. Bake 1 sheet at a time for about 10 minutes, or until the cakes have just started to brown. Remove from the oven and let the cakes cool on the baking sheet for at least 5 minutes before transferring them to a cooling rack.
To make the filling, pour the heavy cream into the bowl of a stand mixer fitted with the whisk attachment. Beat until it forms firm peaks. Carefully fold in the confectioners’ sugar and the jelly.
To assemble the whoopie pies, spread the filling on the flat sides of 2 cakes. Top with 3 or so sliced strawberries and place the other whoopie pie on top. You’ll want filling on both of the whoopie pies to act like a glue.