Peel the apple and remove the core. Cut the apple into 0.5 cm thick slices and soak in calvados for at least 2 hours.
For the dough, mix the flour, milk, eggs, baking powder and salt together well to make a very thick dough. If the dough is still too runny add more flour. Add the oil or butter to the pan and heat it up. Pour some of the dough into the pan, turn an apple slice in the dough and place it on the dough in the pan and pour some more dough over it, so that a somewhat round cake is formed, you can also use round metal molds open at the top and bottom, if you like Has. Bake for about 3 minutes on medium heat, then turn and bake for another 3 minutes.
Sprinkle with cinnamon sugar.
Bake each cake individually and keep warm, unless you have molds, then you bake as much as you have molds at once. In addition, vanilla sauce tastes good when you add some of the calvados.