Bring 1/2 litre of milk and poppy seeds to the boil in a saucepan and simmer for about 3 minutes, stirring continuously. Stir pudding powder, remaining milk, sugar, cinnamon and bitter almond baking oil until smooth. Stir into the boiling poppy seed milk, bring to the boil again briefly and place in a bowl. Cover with cling film and let it almost cool down. Meanwhile, for the dough, stir quark, 6 tablespoons of milk, oil, sugar, salt and lemon zest until smooth.
Mix flour and baking powder and knead. Roll out the quark and oil dough on a floured work surface to a square (approx. 36x36 cm). Spread poppy seed mixture on top, fold in sides and roll up. Separate the egg and coat the roll with egg white. Sprinkle almond flakes on the work surface and turn the roll in it (if necessary, press it down with your hands). Cut the roll into approx. 3 cm thick slices and distribute on 2 baking trays lined with baking paper. Halve the cherries and press one half into the middle of each snail. Bake the trays one after the other in a preheated oven (electric cooker: 200°C/ gas: level 3) for about 20 minutes. Mix egg yolk and remaining milk and brush the snails with it during the last 5 minutes of the baking time.
Sprinkle almond flakes on the work surface and turn the roll in it (if necessary, press it down with your hands). Cut the roll into approx. 3 cm thick slices and distribute on 2 baking trays lined with baking paper. Halve the cherries and press one half into the middle of each snail. Bake the trays one after the other in a preheated oven (electric cooker: 200°C/ gas: level 3) for about 20 minutes. Mix egg yolk and remaining milk and brush the snails with it during the last 5 minutes of the baking time. Let the finished snails cool down