Preheat oven:
Preheat to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment paper.
Mix dry ingredients:
In a large bowl, whisk together flour, cocoa, sugar, baking powder, baking soda, and salt.
Combine wet ingredients:
Add eggs, buttermilk, oil, and vanilla. Mix until smooth and creamy.
Add espresso & water:
Slowly pour in the hot espresso and boiling water. The batter will be thin—this ensures a super moist texture.
Bake:
Pour the batter into pans and bake for 30–35 minutes or until a toothpick inserted in the center comes out clean.
Cool:
Let cakes rest in pans for 10 minutes, then transfer to wire racks to cool completely.
Prepare ganache frosting:
Heat cream and espresso powder in a saucepan until it begins to simmer. Pour over chopped chocolate and rest for 5 minutes. Stir until glossy.
Assemble:
Spread ganache between cake layers, then cover the top and sides. Drizzle extra ganache for a drip effect.
Serve & Enjoy:
Garnish with espresso beans or chocolate curls. Slice and serve with coffee or milk.