1. Preheat oven to 350°F (175°C). Line two 9-inch cake pans with parchment and grease the sides.

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

3. Add eggs, buttermilk, oil, and vanilla extract. Mix until smooth. Slowly stir in boiling water until batter is thin and well blended.

4. Divide the batter evenly into the prepared pans. Bake for 30–35 minutes, or until a toothpick comes out clean. Cool in pans for 10 minutes, then transfer to a wire rack to cool completely.

5. To make the filling, beat heavy cream in a cold bowl until soft peaks form. Add powdered sugar and vanilla. Continue whipping until stiff peaks form. Refrigerate until ready to use.

6. For the ganache, melt chocolate chips and butter in a double boiler or microwave in 30-second intervals. Stir until smooth and let cool slightly.

7. Place one cake layer on a serving plate. Spread the cream filling evenly, leaving a small border. Top with second cake layer.

8. Pour and spread ganache over the top of the cake. Let it drip slightly over the sides.

9. Chill the assembled cake for at least 1 hour before serving to set the layers.