Preheat your oven to 350°F (175°C). Line a 12-cup muffin pan with cupcake liners.

In a large bowl, sift together the flour, cocoa powder, sugar, baking powder, baking soda, and salt.

In a separate bowl, mix together buttermilk, vegetable oil, egg, and vanilla extract until well combined.

Gradually add wet ingredients to the dry ingredients, mixing slowly until just combined. Add the boiling water, and stir until the batter is smooth.

Divide the batter evenly among the cupcake liners, filling each about two-thirds full. Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out clean. Allow cupcakes to cool completely on a wire rack.

While cupcakes are cooling, prepare your frosting. Take about two-thirds of the white frosting and color it with red gel food coloring until the desired vibrant red shade is achieved.

Use a piping bag fitted with a large round tip to pipe the red frosting onto each cupcake, forming a cone shape that resembles a Santa hat.

Pipe a small amount of white frosting onto the tip of the red cone to create the pom-pom. Use mini marshmallows or additional white frosting around the base of the cone to form the fur trim of the hat.