Preheat the oven to 350 degrees F. Butter a 9 x 5-inch loaf pan and line with parchment or waxed (greaseproof) paper.
FOR THE CAKE: Cream the butter and sugar until light and fluffy. Whisk the eggs with the vanilla. Combine with the butter mixture, stirring well. Sift together the flours and salt and fold into the butter mixture alternately with the milk.
Pour the batter into the prepared pan and bake for 40 minutes, or until a skewer inserted in the middle of the cake comes out clean. Turn out onto a wire rack and cool completely, preferably overnight.
If the top of the cake is not flat, trim away any domed part until the top is flat. Cut the cake horizontally into 4 layers.
FOR THE FILLING: Place the ricotta cheese in the bowl of a food processor and process until smooth. Add the cream and sugar and process until well combined. Transfer to a bowl and fold in all the other ingredients, except the Cointreau.
Line the cake pan with an overhanging piece of parchment or waxed paper. Place the bottom layer of cake back in the pan and brush with a little of the Cointreau. Cover with one-third of the ricotta filling. Top with the next layer or cake and repeat until the remaining Cointreau, ricotta filling, and 2 layers of cake have been used, ending with a layer of cake. Refrigerate for at least 1 hour.
FOR THE ICING: Place the chocolate in a double boiler with the coffee. Stir until melted. Add the butter and stir until smooth. Remove from the heat and refrigerate for 15 minutes, or until the chocolate cools to a spreading consistency. Gently remove the cake from the pan and spread with the chocolate icing.
Serve immediately or refrigerate overnight until ready to serve.
Recipe reprinted by permission of Weldon Russell. All rights reserved.