Preheat the oven to 175°C and grease a springform pan.
Wash the lemons hot, dry and finely grate the rind. Pluck the rosemary needles and chop them finely.
Make a shortcrust pastry from the flour, 100g butter, 75g sugar, a pinch of salt, 1 pk vanilla sugar and 1 egg. Knead the chopped rosemary into the dough until you have a tablespoonful and chill it for about 30 minutes.
Roll out the dough thinly on a floured work surface and place in the springform pan. Form a rim and prick the base several times with a fork. Now place the prepared springform pan in the refrigerator.
Separate 2 eggs and beat the egg white very stiff.
Cream 75 g butter, 1 pk. vanilla sugar and 150 g sugar. Stir in 2 egg yolks and 2 eggs separately. Stir in the quark, cream, lemon zest and starch. Add 2 tbsp. lemon curd to the dough and mix well again.
Carefully fold in the beaten egg white quickly.
Take the mould out of the fridge and spread the remaining rosemary on the bottom, press lightly. Spread 2 tbsp. lemon curd well on the base and pour the curd mixture over it. Smooth the mixture and bake the cake in a preheated oven for 60 minutes.
Let it rest for another 10 minutes in the switched off oven and only then take the cake out and let it cool down completely.
If desired, dust with icing sugar.