How to make
Beat the soft butter with the sugar to a smooth cream. Add the egg yolks one at a time and beat the mixture well after each one. Spoon by spoon, add the flour, grated chocolate and vanilla.
Add the beaten to snow egg whites along with a pinch of salt and mix lightly. Add the ground walnuts or almonds and mix gently again.
Pour the mixture into a cake form that you've greased and sprinkled lightly with flour. Bake until ready, turn the cake upside down and glaze it with chocolate icing.