For the cake, line a rectangular springform pan with a high rim (24 x 34 cm) with baking paper. Seal the mould with aluminium foil to prevent the liquid cheese mixture from running out. Mix curd, mascarpone, eggs, pudding powder, sugar, vanilla sugar, 1 pinch of salt, lemon juice and zest briefly with the whisk of the mixer until smooth.
Spread the mixture into the mould. Bake in the preheated oven (electric oven: 175 °C/circulating air: 150 °C/gas: see manufacturer) for 50-60 minutes.
For the sauce, select blueberries, wash and drain. Warm up the jam. Stir in blueberries. Let cool off.
Remove the cake, remove from the edge of the springform pan and let it cool in the pan. Serve with blueberry sauce. More sauces for the cheesecake can be found below.