The rich dark chocolate and creamy, one-of-a-kind icing in this recipe are worthy of the lords and ladies of Downton Abbey. While later made famous by chef Julia Child, this cake was enjoyed in Europe — and made by chefs like Mrs. Patmore — for years before Julia Child came around.
Preheat oven to 350 degrees. Butter and flour one 8-inch round baking pan.
Place the chocolate and ground coffee in the top of a double-boiler. Stir until chocolate is thoroughly melted, then remove from heat.
Cream together the butter and sugar for several minutes until they form a pale fluffy mixture.
In a small bowl, beat together the egg yolks with the vanilla extract, then add to the butter-sugar mixture and thoroughly combine.
In another small bowl, beat the egg whites and salt together until soft peaks are formed.
Pour the melted chocolate into the butter-sugar mixture and thoroughly mix. Then mix in almonds and almond extract. Immediately stir in a quarter of the egg-white mixture so as to lighten the cake. Then mix in the cake flour in small amounts, alternating with the rest of the egg whites.
Turn the batter into the cake pan, then bake in preheated oven for 25-30 minutes. The cake is done when it has puffed and a toothpick inserted around the circumference comes out clean while another stuck in the middle comes out slightly oily.
Allow the cake to cool for 15 minutes. Loosen the cake rim with a knife, then reverse it onto a cooling rack. Allow to thoroughly cool for 1-2 hours before icing.
Mix together the chocolate and espresso powder in the top of a double-boiler. Stir until the chocolate is melted. Remove from the heat and let the chocolate cool until tepid.
In a medium-sized bowl, mix together the sour cream, corn syrup, salt, and vanilla extract. Slowly add the chocolate and stir quickly until the mixture is uniform. Let the icing cool in refrigerator until it is a spreadable consistency, no more than 25 minutes. Spread over the cake with a spatula and then decorate with a design of chopped almonds.