Circle: Roll the chilled dough into a smooth, large circle. Be sure to do this directly on the baking paper or baking sheet, otherwise it will be very difficult to move the formed cake from the table!
Place the filling: Lightly mark the divisions with a stick or a knife. Place the cooled apple mass in the center, leaving about 4-5 cm of free dough around the edge.
Slits on the edges: With a sharp knife or a rolling pin, score the outer edge of the dough radiating inward (toward the filling) every 3-4 cm. You should get many equal strips/tongues of dough around the entire cake.
Shaping ("Petals"): Take the two corners or edges of one strip and pinch them inward/upward to form a pointed "petal." In this way, one by one, press all the sectors of the dough around.
Nut decoration: Press a walnut half into the hollow of each pressed petal (16 halves in total). Not only does it add beauty, but it also tastes great!
Freezing and baking: Before baking, keep the formed cake in the freezer for at least 10 minutes. Place in an oven preheated to 170 °C, slightly below the middle shelf, so that the base is cooked evenly, and the top and especially the nuts will not burn.
Finish: When the apple is bubbling and the top is nicely browned (about 35-40 minutes), pull and cool. Sprinkle with powdered sugar before serving.