Preheat the oven to 350 degrees Fahrenheit. Grease 2 (6-inch) round baking pans with butter.

In a large bowl, sift together flour, cocoa powder, baking soda, baking powder, and salt. Add sugar. Stir until well-combined.

Make a well in the center. Add the egg, oil, milk mixture or buttermilk, and vanilla extract. Whisk just until fully mixed.

Pour the hot coffee and stir just until combined.

Pour the batter evenly into the greased baking pans. Bake for 23-26 minutes or until a toothpick inserted into the center comes out clean.

Transfer the pans to a wire rack and let the cakes cool completely in the pan. You can refrigerate to speed up the cooling.

Add chocolate and cream to a microwave-safe bowl. Microwave in 30-second increments, stirring in between, until fully melted. Set aside to cool.

Pour the ganache evenly over the cakes. Cover with plastic wrap and refrigerate or freeze to set, about 30 minutes to an hour.

Dust with cocoa powder before serving. Enjoy.