Put the curd into a sieve and let it drain overnight. Mix the flour, 2 tablespoons of oil, 1 egg, salt and 125 ml lukewarm water with the dough hooks of the hand mixer to a smooth dough. Form into a ball, brush with remaining oil, wrap in foil and chill for 1 hour. Drain the morello cherries well in a sieve. Roast the hazelnuts in a pan without fat until golden brown, put 2 tablespoons aside. Crush the Amaretti finely in a closed freezer bag.
Cream 25 g room-warm butter and sugar. Stir in remaining eggs one after the other. Add lemon zest and quark and stir until smooth. Roll out or pull the strudel dough very thinly to a rectangle on a large floured tea towel (approx. 40X60 cm). Melt the rest of the butter. Spread the dough thinly with butter and sprinkle with amaretti crumbs and hazelnuts, except for a 3 cm wide rim. Put a 10 cm wide strip of curd cream on the lower short side, leaving the rim free again. Add morello cherries to the quark. Lift the cloth from the bottom side, roll up the strudel and fold the sides. Place it with the seam side down on a baking tray lined with baking paper and spread with butter. Bake in the preheated oven (electric oven: 200 °C/ gas: level 3) for 30-40 minutes.
Spread the dough thinly with butter and sprinkle with amaretti crumbs and hazelnuts, except for a 3 cm wide rim. Put a 10 cm wide strip of curd cream on the lower short side, leaving the rim free again. Add morello cherries to the quark. Lift the cloth from the bottom side, roll up the strudel and fold the sides. Place it with the seam side down on a baking tray lined with baking paper and spread with butter. Bake in the preheated oven (electric oven: 200 °C/ gas: level 3) for 30-40 minutes. Sprinkle with remaining hazelnuts and decorate with Amarettis as desired. Serve warm with whipped cream