Mix flour and baking powder. Separate the eggs, chill the egg whites. Add egg yolks with 150 g sugar, vanilla sugar, 150 g butter in pieces and 2 tbsp. ice-cold water to the flour mixture. Knead first with the dough hooks of the mixer, then quickly with your hands to a smooth dough.
Wrap dough in cling film and chill for about 30 minutes.
Wash and drain the currants. Strip berries from the stalks. Preheat the oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Grease a baking tray (approx. 35 x 40 cm).
Roll out the dough on it. Pre-bake in a hot oven for about 15 minutes.
Beat the egg whites until stiff, adding 200 g sugar. Fold in almonds and currants. Spread the mixture on the pre-baked base. Bake in the oven at the same temperature for about 20 minutes.
Let the cake cool down and dust with icing sugar.