Tuxedo Cake

Instructions

Make the cake:

1. Preheat your oven to 350 degrees. Spray two 9-inch round cake pans with nonstick cooking spray. Set aside.
2. In a medium mixing bowl, whisk together the flour, baking soda, baking powder, and salt. Set aside.
3. In a stand mixer fitted with the paddle attachment, cream the butter at medium speed for about 2 mintues until smooth. Increase the speed to medium-high and add the sugar gradually. Continue beating until light and smooth, about 4 minutes. Turn the mixer off and scrape down the sides of the bowl with a rubber spatula.
4. Add the cocoa powder and vanilla and beat at medium speed for 1 minute more. Stop the machine and scrape down the sides of the bowl again. With the mixer running at medium-low speed, add the eggs, one at a time, beating for 1 minute between each addition. Scrape down the sides of the bowl.
5. Combine the water and milk in a saucepan and bring to scalding (small bubbles form around the edge of the pan). Remove from the heat.
6. With the mixer at low speed, add the flour mixture, about a ¼ cup at a time. Carefully pour the hot liquid into the batter. Remove the bowl from the mixer and, using a large rubber spatula, finish combining the batter until smooth. Divide the batter evenly between the prepared pans. Lightly tap each pan against the counter to settle the batter and remove air bubbles.
7. Set the pans on the middle rack in the oven. Bake the cakes about 30 to 35 minutes, until they begin to pull away from the sides of the pans and the center springs back when touched lightly.
8. Cool the cakes, in the pans, on a rack for 10 minutes. Turn the cake layers out of the pans and continue cooling on the rack.

Make the buttercream:

1. Place the whites and the sugar in the clean, dry bowl of a stand mixer. Place the mixing bowl over a saucepan filled with about an inch of simmering water (the bottom of the bowl should not sit in the water). Continually whip the egg whites and sugar until the sugar dissolves.
2. Remove bowl from the water and place on a stand mixer fitted with the whisk attachment. Whip until the meringue forms medium peaks (peaks form, but the tips fall over).
3. Switch to the paddle attachment. Add the butter, 2 to 3 pieces at a time, whipping until fully incorporated before adding more. The time it takes to incorporate will get longer and longer as more butter is added.
4. After all the butter is added, add vanilla and liqueur (if using) and continue beating until the buttercream comes together and looks smooth and creamy. If the mixture looks curdled, trasnfer about a quarter of the buttercream to a microwave-safe bowl and heat until the mixture melts. Pour it back into the mixing bowl and beat on medium speed until the frosting becomes smooth and creamy.
5. Use immediately, or refrigerate until ready to use. If using later, allow buttercream to come to room temperature, then beat again before using.

Make the ganache:

1. Place the chopped chocolate in a small mixing bowl. Place the heavy cream in a microwave safe measuring cup and heat in the microwave on high for about a minute -- watch it carefully, don't let it boil over.
2. Pour the hot cream over the chocolate, let sit undisturbed for one minute, then whisk until smooth.

Assemble the cake:

1. Choose a serving plate. Place a dollop of frosting in the center of the plate.
2. Level the cakes (cut off the dome, if one formed while baking). Place one layer, cut-side-up, in the center of the serving plate. Place about a half-cup of buttercream on top of the layer, and spread with an offset spatula, adding more buttercream if needed.
3. Place the second cut-side-down on top of the buttercream. Spread a very thin layer of buttercream all over the top and sides of the cake -- the cake below should still show through (this is called a "crumb coat"). Set the cake in the refrigerator for about half an hour.
4. Remove the cake from the refrigerator and add another layer of buttercream frosting to the top and sides of the cake, so that no cake shows through. Set the cake in the refrigerator for about an hour to set the frosting.
5. Warm the ganache, if necessary, at 10-second intervals in the microwave just until it reaches a pourable consistency. It should be warm, not hot. Pour over the center of the cake and use an offset spatula to push the ganache towards the edges of the cake, letting it drip down the sides.
6. Place the cake in the refrigerator to set the ganache, until ready to serve.