Put 55 grams of the butter and the brown sugar into the sauté pan over low heat to melt together, mix then carefully arrange apple slices close together over sugar and butter to form a pattern. Mix together 125 grams of butter with 1 cup of caster sugar add eggs, vanilla, flour, and milk, and mix together to form the batter. Pour batter on top of apples, spread evenly over, and cover with lid leaving the vent closed to cook for 20 mins on low heat or until skewer comes out clean. Use the splatter cover or plate to turn out while still hot. Serve hot or cold with cream custard or ice cream.
Notes
If using an induction cook top cook on low so you do not burn the bottom of the cake. Which turns out to be the top.