Eggs are broken down with the sugar until white. Add cocoa the walnuts and flour, juice and lemon peel. Stir well and slowly pour the mixture into a baking dish, covered with paper. Bake in a moderate oven. The butter cream to mix very well on foam. Boil the milk with sugar and added thereto the walnuts be scalded. This mixture and vanilla add a little to the butter. Once cool, cut cake horizontally into two or three parts, stick with cream. Top and sides are also coated and decorated optional.