Preparation Steps

• Preheat the oven to 350°F (177°C). Line two baking sheets with parchment paper.
• In a large bowl, sift together flour, cocoa powder, baking powder, baking soda, and salt.
• In a separate bowl, whisk together granulated sugar, buttermilk, vegetable oil, eggs, and peppermint extract until smooth.
• Gradually add the wet ingredients into the dry ingredients, mixing until just combined. Fold in the chocolate chunks.
• Drop rounded tablespoons of batter onto prepared baking sheets, spacing about 2 inches apart.
• Bake for 12-15 minutes or until cakes spring back when lightly pressed. Cool completely on wire racks.
• To make the filling, beat the softened butter until creamy. Gradually add powdered sugar, then peppermint extract, heavy cream and food coloring if using, until fluffy.
• Spread or pipe filling onto the flat side of half the cakes, then sandwich with remaining cakes.
• Refrigerate for 30 minutes before serving for best flavor and texture.