Make a vanilla cake and a chocolate cake as follows: sperate the eggs and beat the yolks with sugar until thik and frothy. Fold in the flour. Beat the egg whites until stiff, fold them into the batter.
Divide the cake batter in two parts. Flavour one part with 2 heaped tbsp cocoa and the other with vanilla. Put each miture into the cake tins. Bake for about 15 min, until the cakes come away from edges of the tin. Turn out onto a cake rack and leave to cool.
Prepare a nut cream by mixing the walnuts with the butter, milk, flour, sugar and rum. Bring to boil, stirring well, then remove from the heat. Leave to cool, then spread over one of the cakes, sprinkle with raisins and put the other cake on top.
To make the chocolate cream, mix the milk with the beaten egg, butter, flour, sugar and cocoa. Heat slowly, stirring, until thick. Don't let the miture boil. Leave to cool a bit, then spread on the top of the cake and leave to rest.
When the cream is stiff, cut the cake into little squares and pile them up on a dish. Mix the milk with 50 g/2 oz sugar and the rum, pour over the cake. Decorate with whipped cream.
Before serving, mix the remaining cocoa with sugar and a little water to make a thick sauce and pour over the the whipped cream.