Peel apples, cut them into slices of approx. 1 cm thickness (approx. 20 slices) and cut out the casing with a heart-shaped cutter (approx. 3 cm Ø). Cut the first and last apple slices into fine cubes. Sprinkle the slices and cubes separately with lemon juice and set aside
Cream fat, 400 g sugar, vanillin sugar and salt with the whisk of the hand mixer. Mix flour, almonds and baking powder. Stir the eggs one after the other, alternating with 1 tbsp. flour each, into the fat-sugar mixture. Stir in the remaining flour. Fold in apple cubes
Grease a fat pan of the oven (approx. 32 x 39 cm) and dust with flour. Add the dough and smooth it down. Spread apple slices evenly next to each other on the dough. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 50 minutes. Mix cinnamon and 25 g sugar and halfway through the baking time, sprinkle the cake with it.
Take the cake out of the oven. Let it cool down for about 3 hours. Mix icing sugar and egg white. Cut the cake into 20 pieces and decorate with the icing
waiting time approx. 3 hours