Peppermint Whoopie Pies

Ingredients (15)

• For cakes:
• 4 Cups all-purpose flour
• 1 Cup Dutch-process cocoa powder (high quality)
• 2.5 Teaspoons baking soda
• 2 Teaspoons salt
• 2 Cups well-shaken buttermilk
• 2 Teaspoons vanilla
• 2 sticks unsalted butter, room temp
• 2 Cups packed brown sugar
• 2 large eggs
• For filling:
• 1.5 Cups (3 sticks) unsalted butter, room temp
• 3 Cups powdered sugar
• 1.5 Teaspoons peppermint extract
• A few drops of red food coloring