Preheat your oven to 350°F (175°C) and grease two 9-inch round cake pans with flour.

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

In a separate bowl, whisk the buttermilk, oil, eggs, and vanilla extract until well combined.

Gradually add the wet ingredients to the dry ones, mixing on low speed until just combined.

Carefully pour in the boiling water and mix on low speed until the batter is smooth and thin.

Divide the batter evenly between the prepared cake pans.

Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.

Let the cakes cool in the pans for 10 minutes before inverting them onto a wire rack to cool completely.

In a large bowl, cream the softened butter with an electric mixer until light and fluffy.

Gradually add the powdered sugar and cocoa powder, mixing on low speed until combined.

Slowly add the milk and vanilla extract, mixing on medium speed until the frosting is smooth and creamy.

Beat the frosting for another 2-3 minutes until it’s light and fluffy.

If your cakes have domed tops, lightly level them with a serrated knife.

Place one cake layer on a serving plate, spreading a generous layer of the fudge frosting on top.

Carefully place the second cake layer on top of the frosting and frost the top and sides of the cake.

Decorate with chocolate shavings, fresh berries, or chopped nuts.

Refrigerate the cake for at least 30 minutes before serving.