For the rhubarb-apple-topfenstrudel, first peel, core and finely dice the apples. Peel the rhubarb and cut into thin slices. Melt butter and simmer apples and rhubarb in it. Season with cinnamon.
In the meantime, mix eggs, sugar, curd cheese, sour cream and lemon zest. Add a handful of raisins according to taste.
Roll out the strudel dough. Place the apple-rhubarb mixture on top and spread the curd mixture on top. Roll up the strudel and press the ends tightly.
Place seam side down on a baking tray lined with baking paper and bake the rhubarb-apple-potato strudel in the oven at 170 °C until crispy.