- 10
Ingredients
- Peanut Butter Filling:
- Cake ingredients: Makes 10
- 1/2 cup (1 stick) unsalted butter, room temperature
- 2 cups sugar
- 1/2 teaspoon salt
- 2 large eggs
- 1 1/2 teaspoons vanilla
- 1 1/2 teaspoons baking soda
- 1 cup buttermilk
- 1 3/4 cups all-purpose flour
- 3/4 cup cocoa powder
- 3/4 cup boiling water
- Filling: Makes 3 3/4 cups
- 1 cup (2 sticks) unsalted butter, room temperature
- 2 cups sifted icing sugar
- 1 jar marshmallow Fluff
- 2 teaspoons vanilla
- 2/3 cup peanut butter
- 1/2 cup unsalted butter, softened (1 stick)
- 3/4 cup icing sugar
- To make vanilla Whoopie Pies:
- Omit cocoa powder and increase flour to 2 1/4 cups, increase vanilla to 2 teaspoons and add 1 teaspoon vinegar or lemon juice with milk.
- Variation:
- Fold 1/2 cup mashed raspberries into filling.
Preparation
Step 1
Preheat oven to 350 degrees.
Cake Ingredients:
Cream together butter and sugar in the bowl of an electric mixer fitted with the paddle attachment until combined, 2 to 3 minutes. Add salt, eggs, and vanilla, and beat just until combined.
In a small bowl, mix together baking soda and buttermilk. Add flour to mixer, alternating with buttermilk mixture, beginning and ending with flour.
In a medium bowl, whisk together cocoa powder and boiling water until smooth. Add to batter and beat until combined.
Fill each muffin cup with a heaping 1/4 cup batter. Transfer muffin pans to oven and bake 9 minutes, rotate pans, and continue baking 9 minutes more. Let cool slightly before transferring muffin tops to a wire rack. Let cool completely; remove parchment paper. Repeat process with remaining batter.
Place a heaping 1/4 cup filling on the bottom side of half of the muffin tops. Top with remaining muffin tops, bottom side down, to form whoopie pies.
Filling:
In the bowl of an electric mixer fitted with the paddle attachment, cream together butter and sugar until pale and fluffy, about 3 minutes. Add Fluff and vanilla and continue mixing until well combined.