Preheat the oven at 170 C.
Grease an oven dish with either butter or oil.
Mix in a large bowl the flour, cornflour, sugar and vanilla.
Add the eggs.
Whisk for a few minutes to break the eggs then add the milk.
Whisk until well incorporated. Pour in the oven dish.
Peel the apples and cut them into cubes. Arrange them on top of the milk mix.
Bake in the oven for 30 - 40 min, until golden brown.