Preheat your oven to 350ºF (175ºC). Grease and dust with cocoa powder either two 8-inch cake pans or three 6-inch pans. Set aside.

In the bowl of a stand mixer, combine the dry ingredients: 2 cups all-purpose flour, 2⅓ cups sugar, 1 cup cocoa powder, 1½ teaspoons baking powder, 1½ teaspoons baking soda, and ½ teaspoon salt. Mix on low speed for about 1 minute to combine.

In a separate bowl, whisk together the wet ingredients: 2 large eggs, 1 cup buttermilk, ½ cup oil, ¼ cup mayonnaise, and 1 tablespoon vanilla extract. Pour the wet mixture into the dry ingredients and mix on medium speed for 2 minutes, scraping the sides and bottom of the bowl as needed to ensure everything is incorporated.

Reduce the mixer speed to low and slowly pour in 1 cup of hot coffee. Mix until just combined—do not overmix. The batter will be thin, which is completely normal.

Evenly distribute the batter between the prepared cake pans and bake for 40 to 45 minutes, or until a toothpick inserted in the center of the cakes comes out clean.

Allow the cakes to cool in the pans for about 15 minutes, then carefully turn them out onto wire racks to cool completely before applying frosting.

Begin by heating ¾ cup of heavy cream until just steaming, then pour it over 1¼ cups of semi-sweet chocolate chips in a bowl. Let the mixture sit undisturbed for 5 minutes, then whisk until smooth to form a ganache. Set aside to cool.

In the bowl of a stand mixer fitted with the whisk attachment, add ¾ cup softened butter and 2 tablespoons cream cheese. Whisk together until smooth and creamy.

Sift in ½ cup cocoa powder and 2 to 3 cups of powdered sugar. Begin whisking—the mixture will appear dry and crumbly at first, but continue mixing until it becomes smooth and fluffy.

Add milk 1 tablespoon at a time until the frosting reaches your desired consistency. Then add 1 teaspoon vanilla extract and ½ teaspoon salt. Whisk on high speed until the mixture is light and airy.

Finally, whisk in the cooled ganache from the first step. The frosting will be soft—if you prefer a firmer consistency for decorating, chill it in the refrigerator for about 20 minutes before using.