Mocha Cake with Espresso Drizzle (Sachin's 50th Birthday Cake!)

1 cup freshly brewed espresso or double-strength coffee
2/3 cup unsweetened cocoa powder, preferably Dutch process
4 eggs
2/3 cup buttermilk
1 1/2 teaspoons vanilla extract
2 2/3 cups cake flour
2 2/3 cups sugar
3/4 teaspoon baking powder
1/2 teaspoon salt
2 sticks (8 ounces) unsalted butter, at room temperature
 
Heat the oven to 350 F. Butter the bottoms and sides of three 8-inch round cake pans. Line the bottom of each pan with a round of parchment paper and butter the paper.
 
In a medium bowl, combine the hot espresso and the cocoa powder, stirring to dissolve the cocoa. Let this mocha mixture stand until cooled to body temperature. Meanwhile, in another bowl, beat the eggs lightly. Whisk in the buttermilk and vanilla until well-mixed.
 
Place the flour, sugar, baking powder, and salt in a large mixing bowl. With the mixer on low, evenly blend the dry ingredients. Add the butter and the mocha mixture, beating until well-blended. Raise the mixer speed to medium and beat until light and fluffy, then add the buttermilk-egg mixture in three additions, scraping well and blending only to incorporate. Divide the batter among the three prepared pans.
 
Bake the cake layers for 30 to 35 minutes, or until a cake tester or wooden toothpick inserted in the center comes out almost clean but still moist. Let cool in the pans for about 10 minutes, then invert onto wire racks. Carefully peel off the paper liners and let the layers cool completely.
 
To assemble the cake, place one layer, flat side up, on a serving plate. Pour 1/2 cup of the Espresso Drizzle onto the center of the layer and spread all the way to the edge, allowing it to drip slightly over the sides. Repeat with the second layer. Set the third layer in place, then pour the remaining drizzle on top and spread to the edges, making sure the glaze drips down the sides, covering all the edges.
 
Makes an 8-inch triple-layer cake, serves 12-16
 

Espresso Drizzle

12 ounces good-quality white chocolate
3/4 cup sweetened condensed milk
6 tablespoons freshly brewed espresso or double-strength coffee
 
Melt the white chocolate in a double boiler, or medium heatproof bowl over a pan of very hot water, or gently in the microwave.
 
Whisk in the sweetened condensed milk and espresso and continue whisking until smooth. Use while warm.
 
Makes about 1 1/2 cups.

From Sky High: Irresistible Triple-Layer Cakes by Alisa Huntsman and Peter Wynne, with minor changes