Separate the eggs for the punch slices. Beat the yolks with most of the sugar and vanilla sugar until foamy. Beat the egg whites with the remaining sugar until stiff and fold in alternately with the flour. Line a baking tray with baking paper, spread the mixture to the height of a finger and bake in a hot oven at approx. 180°C for 10-15 minutes until golden. Lift out and let cool.
In the meantime, slowly melt the chocolate (preferably in a bain-marie) for the punch filling. Mix rum with orange juice and lemon juice. Cut half of the cookie into small cubes and mix well with the rum mixture, the melted chocolate and the jam. Add sugar as needed and mix everything until a compact mass is formed.
Cut the remaining sponge cake into two equal sized plates. Spread one slab with jam, spread the filling mixture and cover with the second slab. Press down lightly and let chill, covered, for a few hours (preferably overnight).
Then spread the top sheet with jam and cover the punch slices with the warmed punch glaze. Let dry and then serve.