Start by whisking together the eggs and sugar for approximately 10 minutes until light pale and fluffy. Mix together the flour and walnuts and carefully fold in, followed by the coffee and melted butter. Turn out onto a lined swiss roll tin 30cm x 15cm and even out. Bake in the oven at 200°C for 10-12 minutes or until springy to touch. Meanwhile make the filling by beating together the softened butter, icing sugar, vanilla and cocoa till light then finally beat in the cream cheese. Spread over the sponge and roll up tightly. To make the coffee glaze, mix together the vanilla, coffee and icing sugar and pour over the swiss roll. Decorate the top with chopped chocolate, extra walnuts and dust with icing sugar.