Deep Chocolate Torte with Coffee Buttercream

Line 2 greased jelly-roll pans, 15 by 10 by 1 inch each, with wax paper and butter and flour the paper, shaking out the excess. In a large bowl with an electric mixer beat the egg yolks, add slowly 1 1/2 cups of the sugar, beating, and beat the mixture until it is thick and pale and forms a ribbon when the beaters are lifted. Add the chocolate and combine the batter well. In another large bowl with clean beaters beat the egg whites until they hold soft peaks, add the remaining 1/4 cup sugar slowly, and beat the mixture until it just holds stiff peaks. Stir one fourth of the whites into the yolk mixture, fold in the remaining whites gently but thoroughly, and pour the batter into the pans, spreading it evenly. Bake the cake layers in the middle of a preheated 375 °F. oven for 18 to 20 minutes, or until a tester comes out clean. Let the cake layers cool in the pans, covered with kitchen towels, on large racks. Invert the cake layers onto the racks and remove the wax paper carefully.