Flourless Chocolate Cake
Chocolate and coffee: is there any finer combination? This flourless cake gets all of its height from the egg whites. (You can sift confectioners’ sugar over a paper doily to make a design on the top of the cake.)
Adjust the oven rack to the middle of the oven. Preheat the oven to 250°F (120°C). Grease and flour a 12-inch springform pan; line the bottom with a wax- or parchment-paper circle and then grease and flour the paper.
In a mixing bowl, beat the egg yolks until smooth. Gradually beat in half of the hot chocolate mixture, a little at a time, beating constantly. Add the mixture in the mixing bowl to the remaining hot chocolate mixture and continue cooking until the mixture thickens slightly. Stir constantly. Add the instant coffee powder, coffee liqueur, and vanilla. Remove from the heat, transfer to a large bowl, and let cool slightly.
In a clean bowl, beat the egg whites on medium-low speed until frothy. Increase to high speed and continue beating until soft peaks form. Add the remaining 1/4 cup superfine sugar, 1 tablespoon at a time, beating until the peaks are stiff but not dry. Gently fold the whites into the chocolate mixture. Pour the batter into the prepared springform.
Bake for 3 hours. The cake will rise to the top of the pan but then will deflate as it cools.
Let the cake cool to room temperature in the pan. Then cover it (still in the pan) tightly with plastic wrap and chill overnight.
To serve, run a knife around the sides of the pan and remove the sides. Invert the cake onto a serving plate. Remove the pan bottom and the paper. The cake may be frozen at this point, wrapped tightly in plastic wrap and then overwrapped in foil. Before serving, let the cake defrost, fully wrapped. Sift confectioners’ sugar over the top, or spread with whipped cream or crème fraîche.