Wash the apples, grate them dry and cut out the cores. Cut apples into wafer-thin slices and sprinkle with lemon juice. Spread the bottom of a springform pan (24 cm Ø) thickly with butter and sprinkle with sugar.
Spread apple slices on top. Sprinkle almond flakes over it. Roll out the puff pastry and cut out a circle (25 cm Ø). Lay on the apples, press the edge a little bit. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 30-35 minutes.
Remove and immediately fall onto a plate. Stir apple jelly until smooth and immediately spread the apples with it. Cut out small apples from the remaining dough and place them on a baking tray lined with baking paper.
Bake at the same temperature for about 10 minutes. Let the cake cool down. Arrange on a plate decorated with apples and mint. Serve with vanilla sugar.