For the shortcrust pastry, knead the ingredients into a smooth dough and refrigerate.
Grease a springform pan and set aside.
In the meantime, wash, peel, core and dice the apples.
Line the springform pan with the dough and press up an approx. 3 cm high edge.
Mix the egg yolks, cinnamon, sugar, sour cream, nuts and flour together. Beat the egg whites until stiff and fold into the sauce. Carefully fold in the apple cubes. Pour the mixture onto the shortcrust pastry and smooth it out.
Bake in a preheated oven at 180 ° C for 40-50 minutes.