Make the Cake:

Preheat oven to 350°F (175°C). Grease and flour two 8-inch round cake pans (or line with parchment).

Mix Dry Ingredients:

In a large bowl, whisk together flour, cocoa powder, baking soda, baking powder, and salt.

Mix Wet Ingredients:

In another bowl, combine sugars, eggs, oil, vanilla, and buttermilk. Whisk until smooth.

Combine & Add Hot Liquid:

Add the wet ingredients to the dry. Stir in the hot water or coffee slowly until the batter is smooth and thin.

Bake:

Divide batter between pans and bake for 25–30 minutes, or until a toothpick comes out clean. Cool completely before frosting.

Make the Frosting:

In a large bowl, beat softened butter until creamy.

Gradually add powdered sugar, followed by heavy cream, peppermint extract, and salt. Beat until light and fluffy.

Optional: swirl in a tiny bit of red food coloring for a marbled peppermint look.

Assemble the Cake:

Place one cooled cake layer on a serving plate. Spread a generous layer of frosting on top.

Add the second layer and frost the top and sides.

Garnish with crushed peppermint candies and chocolate shavings.