Grease a fat pan (32 x 39 cm; at least 3.5 cm deep) and dust with flour. Peel, quarter, core and chop apples. Bring to the boil with lemon juice, 100 ml apple juice and 75 g sugar and simmer for about 3 minutes.
Mix 35 g starch and 100 ml apple juice. Stir into the apple compote, continue to simmer for about 1 minute. Then let it cool down for about 30 minutes.
Melt 250 g butter at low heat. Mix 350 g flour, 200 g sugar, 1 packet of vanilla sugar, 1 pinch of salt and cinnamon. Add the liquid butter, kneading everything first with the dough hooks of the hand mixer and then briefly with your hands to form crumbles.
Sprinkle 1 tablespoon of flour over it, shake briefly.
Stir 250 g butter, 200 g sugar, 1 packet vanilla sugar, lemon zest and 1 pinch of salt for about 8 minutes until creamy.
Stir in eggs one by one, alternating with 100 g starch. Mix 250 g flour, almonds and baking powder, stir in portions briefly. Spread on the fat pan. Spread compote on top. Sprinkle with crumbles and grind between your fingers.
Bake in the preheated oven (electric oven: 200 °C/circulating air: 175 °C/gas: level 3) for about 45 minutes. Cool down. Dust with icing sugar.