Filling: Wash the apples, peel them, then put them on the grater with large holes. Put it on the fire in a saucepan, together with the sugar (according to taste, depending on how sweet the apples are) and let it harden over medium heat, until you can reduce the juice that leaves it. At the end add cinnamon and lemon peel. Mix well, then leave to cool.
Countertop: In a bowl put eggs together with salt powder, vanilla sugar and sugar. Mix well until all the sugar dissolves and a creamy composition is obtained. Add milk and oil alternately and mix. At the end, add the flour mixed with the baking powder and mix well.
Wallpaper a tray measuring 21x24 cm with oil and flour. Pour half of the dough into the pan. Place in the preheated oven at 180 degrees C, for about 10 minutes. After this time has elapsed, remove the tray from the oven, pour the apples, level them, then place the rest of the dough on the entire surface. Level it lightly and put it back in the oven until it browns nicely on top and passes the toothpick test.
Remove from the oven and allow to cool. It can be powdered with vanilla powdered sugar. Portion and serve.