Melt butter in a pot. Coarsely crumble the butter biscuits and Amarettini with your hands. Pour butter over them and knead again. Grease a springform pan (26 cm Ø) with oil. Put biscuit-butter crumbs into the form, press them down as a base and thick rim (approx. 2 cm high and 1.5 cm wide) and put them in a cool place.
Peel 2 apples, remove seeds and cut into cubes. Wash 2 apples, grate them dry, cut out the core with an apple corer and cut the apple into thin rings. Stir curd, sour cream, eggs, sugar and cinnamon until smooth, add the apple cubes.
Spread the quark and apple mixture on the biscuit base and smooth it down. Spread apple rings on top, spread with apple jelly and bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 40 minutes. Remove from the oven and let cool down for 1-2 hours. Whipped cream tastes good with it.