Melt the butter. Finely crumble the rusk. Mix breadcrumbs, 3 tablespoons sugar, rusk and melted butter. Take 2 tablespoons aside. Spread the rest of the crumb mixture on the bottom of a greased fat pan of the oven and press it down to a smooth base. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 8 minutes, let cool down.
In the meantime, stir cream cheese, 250 g sugar, vanilla sugar, lemon and orange peel and vanilla flavouring with the whisks of the hand mixer until creamy. Add flour, then stir in eggs and egg yolks one by one. Stir in sour cream and spread on the crumb base. Bake in the preheated oven (electric cooker: 250 °C/ convection oven: 225 °C/ gas: level 5) for approx. 12 minutes. Reduce temperature to 125 °C and bake for 1 hour. Then let cool off well. Drain the cherries and collect the juice. Add water to 1/2 liter. Mix sauce powder and 50 g sugar. Stir with 6 tablespoons of the juice mixture until smooth. Boil up the rest of the mixture. Add mixed powder while stirring, bring to the boil.
Drain the cherries and collect the juice. Add water to 1/2 liter. Mix sauce powder and 50 g sugar. Stir with 6 tablespoons of the juice mixture until smooth. Boil up the rest of the mixture. Add mixed powder while stirring, bring to the boil. Fold in cherries. Sprinkle the cheesecake with retained crumbs and ground pistachios, cut into pieces and serve with the cherry sauce
waiting time approx. 2 hours