Is broken yolks with sugar until white. Add ground walnuts, cocoa, flour and egg whites, beaten to snow. Everything is very slow stir well and pour into a baking dish, covered with paper. Bake in a moderate oven. The butter cream to mix with 150 g of sugar until white. Eggs are broken with 100 g of sugar to warm thickening. Add the grated chocolate. After the mixture cooled down, mixed with butter. Mix everything well. Cool base was cut into three pieces and filled with cream. Top and sides also smeared with cream. Decorate optional.