Peel, core, quarter and slice the apples. Heat 3 tablespoon butter in a pan and add the apple slices. Mix the sugar and cinnamon and sprinkle over the apples. Simmer for 10 minutes while stirring several times.
Whisk the eggs and stir in the flour and salt. Mix in 2 tablespoon butter, milk and vanilla flavor.
Grease a large ovenproof casserole dish or pie pan (30 cm). Spread the steamed apples on the bottom of the pan. Pour the dough over it. Bake everything in a preheated oven at 220 degrees for about 20 minutes until golden brown. Then dust with powdered sugar.