01 -
Preheat the oven to 350°F. Grease and line three 8-inch round cake pans with parchment paper.
02 -
Whisk together the flour, granulated sugar, baking soda, baking powder, and salt in a large mixing bowl.
03 -
Add buttermilk, vegetable oil, eggs, and vanilla extract to the dry mixture. Mix until thoroughly blended.
04 -
Gradually stir in the hot brewed coffee until the batter is smooth and fluid.
05 -
Distribute the batter evenly among the prepared pans. Bake for 30–35 minutes, or until a toothpick inserted in the center emerges clean.
06 -
Allow cakes to cool in the pans for 10 minutes, then remove and transfer to a wire rack to cool completely.
07 -
Heat heavy cream in a saucepan over moderate heat until steaming but not boiling.
08 -
Pour hot cream over the chopped dark chocolate in a bowl. Let rest for 2 minutes, then stir until fully melted and smooth. Add unsalted butter and mix until glossy.
09 -
Spread the cooled ganache between cake layers and over the top and sides for a smooth finish. Garnish if desired.