Grease a fat pan of the oven. Melt 100 g butter. Crumble the rusk and mix with the melted butter. Put the mixture into the fat pan and press it smooth. Chill for about 20 minutes. In the meantime, stir 150 g butter with the diabetic sweetener and vanilla pulp until creamy. Add cream cheese, sour cream, quark, lemon peel and eggs and stir until smooth.
Mix flour with starch and also stir in. Spread the cheese mixture on the rusk base until smooth. Bake in the preheated oven (electric cooker: 200 °C /circulating air: not suitable/ gas: level 3) for about 10 minutes. Switch the temperature down (electric oven: 100 °C /gas: level 1) and bake for about 1 1/4 hours. Let the cake cool down, cut into 12 squares and divide them diagonally. Wash lemon and lime, dab dry and cut into very thin slices. Decorate cake pieces with it