- 3 cups all purpose flour (12.75 ounces, 363 grams)
- 2 teaspoons baking soda (10 grams)
- ½ teaspoon baking powder (2.45 grams)
- ½ teaspoon salt (2.5 grams)
- 1 cup Dutch-processed unsweetened cocoa powder (3.2 ounces, 92 grams)
- 2 cups strong brewed coffee (8 ounces, 230 grams)
- ½ pound (2 sticks) unsalted butter, softened (8 ounces, 227 grams) plus additional for the pans
- 3 cups granulated sugar (21 ounces, 600 grams)
- 4 large eggs (6.8 ounces, 193 grams), at room temperature
- 14 ounces coarsely chopped extra-bitter chocolate (minimum 70 percent cacao content) (397 grams)
- 3 cups heavy cream (24.36 ounces, 696 grams)
- About ½ pound block of bittersweet chocolate for chocolate curls for decorating, optional
- Whipped cream, for serving, optional
- Fresh berries, for serving, optional
- Two 9-inch round cake pans
- Sifter
- Electric mixer
- Cake tester
- Offset spatula
- Cake stand or serving platter
- For the cake:
- Position a rack in the center of the oven. Grease two 9-inch round cake pans with unsalted butter and line the bottoms with parchment or waxed paper rounds. Grease the rounds.
- Sift the flour, baking soda, baking powder, and salt onto a piece of parchment or waxed paper and set aside.
- Place the cocoa in a small bowl and whisk in the coffee a little at a time until smooth.
- In the bowl of an electric mixer fitted with the paddle attachment, cream the butter, then beat in the sugar. Beat on high speed until very light and fluffy, 6 to 8 minutes.
- Preheat the oven to 350°F. Add half the flour mixture to the butter mixture and mix on low speed until just incorporated. Add the eggs one at a time, beating to incorporate after each addition. Add the cocoa-coffee mixture and beat to incorporate. Add the remaining flour mixture and mix until just incorporated.
- Divide the batter evenly between the two pans and bake on the center rack, turning the pans from back to front during the baking, until a cake tester inserted into the middle of the cakes comes out completely clean, about 45 minutes. Let cool in the pans on racks for about 30 minutes, then slide a thin knife or offset spatula around the sides of the pans and turn them over to unmold the cakes onto the racks. Carefully peel the parchment or waxed paper rounds from the bottoms of the cakes and allow to cool completely, at least 30 to 40 minutes more, then cover and refrigerate the layers. This will make the cake less crumbly and easier to slice when cutting the layers. Make the ganache icing while the cake cools.
- For the ganache:
- Place the chocolate in a heatproof bowl. In a medium saucepan over medium-high heat, bring the cream to a boil. Pour the hot cream over the chocolate, and let it sit for 3 minutes. Whisk until thoroughly combined and slightly cooled, then cover tightly with plastic wrap and refrigerate for at least 4 hours. Once the ganache is chilled, whisk until just fluffy.
- To assemble and serve:
- Using a long, serrated knife, cut the cake into thin layers horizontally. Place one hand flat on top of the cake. Starting at the edge, slice into the cake about ½ inch from the top and using a sawing motion move the knife into the cake about 1 inch. Then, still slicing back and forth, turn the cake (counterclockwise if you are right-handed, clockwise if you are left-handed) on the table, going around the circumference of the cake. After the first full circle is completed, holding the knife level, dig into the cake another inch and turn the cake again in the same direction. Repeat until you have sliced all the way through the cake, then remove this top layer and repeat three more times to obtain 4 layers from each of the two cakes. Place the bottom cake layer on the serving platter you wish to use and spread a thin layer of ganache over it. Repeat with the other 7 layers. Use the remaining ganache to cover (“mask”) the outside of the cake. First give it a thin coat; this is called the “crumb coat” because it sets the ganache over the outside crumbs, preventing them from appearing on the outside of the cake. Refrigerate for an hour after this “crumb coat,” then ice the cake a second time with the remaining ganache. Finish with chocolate curls