Pour flour on the work surface, make a hollow in the middle, add egg yolk and 2-3 tablespoons of iced water, add 50 g of sugar, fat in flakes and the lemon peel on the edge of the flour and knead everything into a smooth dough.
Cover and leave to rest in a cool place for about 1 hour. Drain the cherries on a sieve. Mix the sour cream, eggs, vanillin sugar and remaining sugar. Roll out the dough to a circle (29 cm Ø), place it in an ovenproof, greased mould (25 cm Ø), prick the base several times with a fork and spread the cherries on top.
Pour over the sour cream egg icing and bake in the preheated oven (electric: 200°C/ gas: level 3) for approx. 45 minutes. Sprinkle almond flakes over the tart halfway through the baking time. Sprinkle the tarte with sugar crystals before serving.