Peel the apple, remove the core and cut the apple into small pieces or thin slices.
Mix the egg yolks with salt, sugar, flour, baking powder, milk and mineral water with a hand blender (be careful, something splashes). Beat the egg white until stiff and fold in. Finally, carefully fold in the apple pieces.
Heat the oil in a pan and bake the pancakes until they are a nice color on both sides.
Sprinkle with cinnamon sugar and serve immediately if possible.
My grandma always served these pancakes with lentil soup or vegetable stew.