Preheat your oven to 350°F or 175°C. Grease two round cake pans with butter or oil. Line the bottoms with parchment paper. This helps the cakes release easily later. Proper pan preparation prevents sticking and keeps the cake layers smooth and beautiful.

In a large bowl, add flour, sugar, cocoa powder, baking soda, baking powder and salt. Whisk everything together slowly until evenly mixed. This step spreads the cocoa flavor properly throughout the batter and helps create an even cake texture after baking.

Crack eggs into the bowl and add buttermilk, vegetable oil and vanilla extract. Mix gently using an electric mixer or whisk. The batter should begin looking smooth and creamy. Buttermilk helps create the famous soft texture that makes this cake extra moist.

Slowly pour hot coffee or hot water into the batter while mixing carefully. The batter will look thinner than normal cake batter. That is completely fine. Hot coffee helps deepen the chocolate flavor and creates a richer taste in every bite.

Divide the batter evenly between the prepared cake pans. Smooth the tops gently using a spatula. Tap the pans lightly on the counter to remove air bubbles. This helps the cakes bake evenly and keeps the layers soft and balanced.

Place the cake pans into the oven carefully. Bake for 30 to 35 minutes until a toothpick comes out clean. The tops should feel soft but set. Avoid overbaking because that can dry the cake and reduce its moist texture.

Remove the cakes from the oven and let them cool in the pans for 10 minutes. Then transfer them onto a cooling rack. Cooling fully is very important before frosting. Warm cakes can melt frosting and make decorating difficult and messy.

In a clean bowl, beat softened butter until creamy. Add powdered sugar and cocoa powder slowly while mixing. Pour in heavy cream and vanilla extract. Continue mixing until fluffy and smooth. The frosting should look rich, creamy, and easy to spread.

Place one cake layer onto a serving plate. Spread frosting evenly across the top. Add the second cake layer carefully. Cover the top and sides with remaining frosting. Smooth gently with a spatula. Slice and serve once the frosting sets slightly.