Ingredients
CakeAll-purpose flour - 1 3/4 cups
Sugar - 2 cups
Good cocoa powder - 3/4 cups
Baking soda - 2 tsp
Baking powder - 1 tsp
Kosher salt - 1 tsp
Buttermilk - 1 cup, shaken
Vegetable oil - 1/2 cup
Extra-large eggs - 2 , at room temperature (Used egg replacer)
Pure vanilla extract - 1 tsp
Freshly brewed hot coffee - 1 cup
Chocolate Buttercream Frosting
Good semisweet chocolate - 6 ounces
Unsalted butter - 1/2 pound, at room temperature
Extra-large egg yolk - 1 , at room temperature
Pure vanilla extract - 1 tsp
Confectioners' sugar - 1 1/4 cups, sifted
Instant coffee powder - 1 TBSP
Steps
1. Preheat the oven to 350º F. Butter two 8-inch x 2-inch round cake pans. Line with parchment paper, then butter and flour the pans. I used 3 6" round cake pans.2. Sift the flour, sugar, cocoa, baking soda, baking powder, and salt into the bowl of an electric mixer fitted with a paddle attachment and mix on low speed until combined. In another bowl, combine the buttermilk, oil, eggs, and vanilla. With the mixer on low speed, slowly add the wet ingredients to the dry. With mixer still on low, add the coffee and stir just to combine, scraping the bottom of the bowl with a rubber spatula.
3. Pour the batter into the prepared pans and bake for 35 to 40 minutes, until a cake tester comes out clean. Cool in the pans for 30 minutes, then turn them out onto a cooling rack and cool completely.
4. Chop the chocolate and place it in a heat-proof bowl set over a pan of simmering water. Stir until just melted and set aside until cooled to room temperature.
5. In the bowl of an electric mixer fitted with a paddle attachment, beat the butter on medium-high speed until light yellow and fluffy, about 3 minutes. Add the egg yolk and vanilla and continue beating for 3 minutes.
6. Turn the mixer to low, gradually add the confectioners' sugar, then beat at medium speed, scraping down the bowl as necessary, until smooth and creamy.
7. Dissolve the coffee powder in 2 teaspoons of the hottest tap water. On low speed, add the chocolate and coffee to the butter mixture and mix until blended. Don't whip!
8. Place 1 layer of cake, flat side up, on a flat plate or cake pedestal. With a knife or offset spatula, spread the top with frosting. Place the second layer on top, rounded side up, and spread the frosting evenly on the top and sides of the cake.