For the currant mousse cake, whip the egg whites, add 3 tablespoons of granulated sugar and beat until ready. Beat the yolks, powdered sugar and vanilla sugar until foamy.
Add poppy seed oil and stir again. Then add rum and mineral water and mix in the flour. Carefully fold in 1/3 beaten egg white.
Pour the dough into a greased and floured baking pan and bake briefly at approx. 160 °C. In the meantime, whip the remaining beaten egg whites again with 3 tablespoons granulated sugar until stiff.
Sprinkle the pre-baked cake with the rasped currant and brush with the beaten egg whites – finish baking.