SERVES 10 TO 12
If using 9-inch cake pans, note that the layers will be quite thin. For an accurate measurement of boiling water, bring a full kettle of water to a boil, then measure out the desired amount. Click here for more information on frosting a layer cake. See the sidebars that follow the recipe.
|
½ |
cup (1½ ounces) Dutch-processed cocoa powder, plus extra as needed |
|
1½ |
cups (7½ ounces) all-purpose flour |
|
1 |
teaspoon baking soda |
|
½ |
teaspoon baking powder |
|
¼ |
teaspoon salt |
|
1¼ |
cups boiling water |
|
4 |
ounces unsweetened chocolate, chopped |
|
1 |
teaspoon instant espresso powder or instant coffee powder |
|
10 |
tablespoons unsalted butter, softened |
|
1½ |
cups packed (10½ ounces) light brown sugar |
|
3 |
large eggs, room temperature |
|
½ |
cup sour cream, room temperature |
|
1 |
teaspoon vanilla extract |
|
1 |
recipe buttercream frosting (recipes follow) |
1. Adjust oven racks to upper-middle and lower-middle positions and heat oven to 350 degrees. Grease three 8- or 9-inch round cake pans, line with parchment paper, grease parchment, then dust with cocoa. Whisk flour, baking soda, baking powder, and salt together in large bowl. In medium bowl, whisk boiling water, chocolate, ½ cup cocoa, and espresso powder together until smooth.
2. Using stand mixer fitted with paddle, beat butter and sugar together on medium speed until light and fluffy, 3 to 6 minutes. Beat in eggs, one at a time, until combined, about 30 seconds. Beat in sour cream and vanilla until incorporated.
3. Reduce speed to low and add flour in 3 additions, alternating with chocolate mixture in 2 additions, scraping down bowl as needed (do not overbeat). Give batter final stir by hand.
4. Divide batter evenly among prepared pans, smooth tops with rubber spatula, and gently tap pans on the counter to release air bubbles. Bake until toothpick inserted in center of cake comes out with few crumbs attached, 15 to 20 minutes, rotating pans halfway through baking.
5. Let cakes cool in pans on wire rack for 10 minutes. Remove cakes from pans, discard parchment, and let cool completely, about 2 hours, before frosting. (Cooled cakes can be wrapped tightly in plastic wrap and kept at room temperature for up to 1 day. Wrapped tightly in plastic, then aluminum foil, cakes can be frozen for up to 1 month. Defrost cakes at room temperature before unwrapping and frosting.)
6. Line edges of cake platter with 4 strips of parchment paper to keep platter clean. Place 1 cake layer on prepared platter. Place about 1 cup frosting in center of cake layer and, using large spatula, spread in even layer right to edge of cake. Repeat with second and third layer, spreading frosting on top layer until slightly over edge. Gather more frosting on tip of spatula and gently spread icing onto side of cake. Smooth frosting by gently running edge of spatula around cake and leveling ridge that forms around top edge, or create billows by pressing back of spoon into frosting and twirling spoon as you lift away. Carefully pull out pieces of parchment from beneath cake before serving. (Assembled cake can be refrigerated for up to 1 day. Bring to room temperature before serving.)