Preparation:
- Blend the butter into 150 g white sugar and the vanilla sugar.
- Separate the egg albumen from the yolks and then progressively add the yolks to the butter/sugar mixture.
- Whip the egg whites until semistiff, and then add the rest of the sugar while beating the mixture until
   the egg whites hold stiff, glossy peaks.
- Mix the flour and almonds together before pouring over the mixture.
- Allow the beaten egg whites to slide over the top, then carefully fold everything into the batter.
- Pour the batter into a 26 cm dia. greased springform pan and bake in a preheated oven at approx. 175° for about 
    an hour (make the toothpick test to see if the cake is done).
- Remove the cake from the tin and allow to cool.
- Slice off the base horizontally and fill the inside with redcurrant jam.
- Sprinkle with icing sugar and serve with whipped cream to taste.