This is my old recipes, when my sons were small I made it very often, they loved this cake.
To prepare the custard : Prepare the custard in the same way as the instructions on the back of package, just add less water or milk to get a thick custard. It have to be was very thick. Let to cool slitely and spread it over batter.
Preheat the oven to 190C, line a big tin with greaseproof paper. With an electric mixer, cream the butter and sugar together until light and fluffy. Beat in the egg, 1 at a time. Stir in the flour , cornflour, baking powder, vanilia powder. Mix well to combine everything. Divide the batter in half, one of them put on the bottom of tin.
Peel the apples and rub on a grater with large mesh, stir in the breadcrumbs and put over the custard.
Cover the apples with the remaining batter.
Bake in preheated oven for 45-50 minutes until golden on the top
Cake is very delicious 🙂 I recommend 🙂