Peel small rolls from the chocolate with a peeler and chill. Whip the cream until stiff, chill.
Separate eggs and freeze 3 egg whites. Mix all the egg yolks, sugar and vanilla sugar in a metal bowl with a whisk or mixer. Whip in a hot water bath for 10-15 minutes to a thick foamy cream.
Stir in rum and coffee.
Beat 3 egg whites until stiff. Remove the egg yolk mixture from the water bath and fold in the beaten egg white in portions. Pour the cream immediately into cups or dessert bowls. Serve immediately with 1 dollop of cream, chocolate rolls and cocoa.