Chocolate Whoopie Pies | La Cucina Grandinetti

Ingredients

• 2 cups all-purpose flour
• 1/2 cup Dutch-process cocoa powder
• 1 teaspoon instant espresso powder
• 1 1/4 teaspoons baking soda
• 1 teaspoon salt
• 1 cup well-shaken buttermilk
• 1 teaspoon vanilla
• 1 stick (1/2 cup) unsalted butter, softened
• 1 cup packed brown sugar
• 1 large egg
• 1 1/2 cups confectioners sugar, sifted
• 2 cups marshmallow cream such as Marshmallow Fluff