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

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

In a separate bowl, beat together eggs, buttermilk, oil, and vanilla extract.

Add the wet ingredients to the dry ingredients and mix until just combined. Be careful not to overmix.

Gradually stir in the hot coffee until the batter is smooth. The batter will be thin.

Pour the batter evenly into 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.

Place the chocolate chips in a heatproof bowl.

Heat the heavy cream in a small saucepan over medium heat until it just begins to simmer. Do not boil.

Pour the hot cream over the chocolate chips. Let it sit for 5 minutes without stirring.

Gently whisk the mixture until smooth. Stir in the butter until melted and incorporated.

Let the ganache cool at room temperature for about 30 minutes, or until it reaches a spreadable consistency.

Place one cake layer on a serving plate. Spread a generous amount of ganache over the top.

Top with the second cake layer and frost the top and sides of the cake with the remaining ganache.

Serve immediately or store at room temperature.