• Mix the sugar, egg yolk, lemon zest and vanilla sugar with the hand mixer. Sift the flour with the baking powder and the salt into the mixture. Knead the dough evenly by hand.
• Cover the bowl and place in the fridge for about 30 minutes

Prepare the topping

• Beat the egg whites until stiff. Then first let the sugar trickle in gradually. Finally add the strength. Carefully fold the currants into the mixture by hand.

Bake

• Preheat the oven to 180 degrees. Bake the dough for 20 minutes and then remove it from the oven.
• Roll out the dough and place in the springform pan. Pull up the edge of the dough.
• Spread the currant mixture evenly on the pre-baked dough. Bake the cake for another 35 minutes.