Grease a 26cm springform cake tin and preheat oven to 200 C / Gas 6.
Beat 2 egg yolks with water, sugar and vanilla until fluffy. Mix flour, baking powder and salt and beat well into the egg-yolk mixture. Beat 2 egg whites until stiff and fold into the yolk mixture. Pour mixture into prepared springform tin and bake in the preheated oven for about 30-40 minutes.
Leave base to cool and slice in half to form two thin layers.
For the filling, beat 3 egg yolks, sugar, lemon juice and zest until fluffy. Gradually stir in the cottage cheese.
Dissolve the gelatine as directed on packet. Beat 3 egg whites and cream separately until stiff. Now fold the gelatine, egg whites and cream into the cottage cheese mixture.
Lay the bottom layer of the cake back into the springform tin and spread the cheese filling over it. Place the second layer on top.
Put the cake in the fridge to cool and set. Finally, dust the cake with icing sugar to serve.