Grease a springform pan (26 cm Ø) and dust with flour. Separate the eggs. Mix butter with sugar and vanilla sugar until creamy. Stir in curd, egg yolks, pudding, sauce powder and cream one after the other.
Stir in the milk briefly. Beat egg whites with salt until stiff, fold into the cheese mixture. Pour the mixture into the mould. Bake in the preheated oven (electric cooker: 150 °C/ convection oven: 125 °C/ gas: see manufacturer) for approx. 1 1/4 hours.
Let it cool down in the open oven. Keep cool overnight.
Wash and clean the strawberries and, depending on size, cut them in half or quarters. Stir icing sugar with lemon juice until smooth. Remove the cake from the tin. Spread the icing on the cake, let it dry. Spread strawberries on the cake just before serving.