Stir milk, egg, lemon zest, sugar and salt well. Put the sliced breadcrumbs in a bowl and pour over a part of the milk- and egg mixture. Peel the apples, remove seeds and cut into thin slices. Put the apples in a buttered form and the soaked breadcrumbs, the top layer must be roll.
Pour the rest of the egg milk over it, top with a few butter flakes and bake in a preheated oven at 165 ° for about 30 - 45 min. golden brown.
When everything is ready, sprinkle with sugar cinnamon and serve. It goes well with fruit sauce, vanilla sauce or wine foam sauce.