4 oz unsweetened chocolate, chopped
1/4 C Dutch-processed cocoa
1 1/4 C boiling water
3/4 C unbleached all-purpose flour
3/4 C cake flour
1 tsp baking soda
1/4 tsp salt
16 T unsalted butter, softened, but still cool
1 1/2 C packed dark brown sugar (Add 1 T of molasses per 1 C of light brown sugar to create dark brown sugar)
3 large eggs, at room temperature
1/2 C sour cream
1 tsp vanilla extract
1. Adjust the oven racks to the upper and lower middle positions; heat the oven to 350 degrees. Meanwhile, grease three 8-inch cake pans and line the bottom of each pan with a round of parchment paper. Combine the chocolate and cocoa in a medium bowl; pour boiling water over and whisk until smooth. Sift together the flours, baking soda, and salt on in a medium bowl, set aside.
2. Beat the butter in the bowl of a standing mixer at medium-high speed until creamy, about 1 minute. Add the brown sugar and beat at high speed until light and fluffy, about 3 minutes. Stop the mixer and scrape down the bowl with a rubber spatula. With the mixer on medium-high speed, add the eggs, one at a time, beating 30 seconds after each addition. Reduce the speed to medium; add the sour cream and vanilla and beat until combined, about 10 seconds. Stop the mixer and scrape down the bowl. With the mixer at a low speed, add about a third of the flour mixture, followed by about half of the chocolate mixture. Repeat, ending with the flour mixture; beat until just combined, about 15 seconds. Do not over beat. Remove the bowl from the mixer; scrape the bottom and sides of the bowl with a rubber spatula and stir gently to thoroughly combine.
Divide the batter evenly among the cake pans and smooth the batter to the edge of each pan with a rubber spatula. Place 2 pans on the lower-middle rack and 1 on the upper-middle rack. Bake until a toothpick or skewer inserted in the center comes our clean, 20-23 minutes. Cool the cakes on wire racks 15-20 minutes. Run a knife around each pan perimeter to loosen. Invert each cake onto a large plate; peel off the parchment and re invert onto a rack. Cool completely.
4. Assemble and frost the cake.
I made this into cupcakes with orange frosting. YUM!!!!!!!!!!!
From Cook's Illustrated The New Best Recipe cook book.