Generously grease a round 9-inch cake pan. Slice the apples using a mandoline to obtain very thin slices.

Melt the butter in a medium saucepan. Add the brown sugar, cinnamon, nutmeg, cloves, and vanilla. Cook over medium heat for about 3 minutes until smooth and slightly thickened. Pour the caramel into the greased cake pan and top with the apple slices.

Preheat the oven to 325 degrees F. Beat the remaining butter and brown sugar until creamy. Add the eggs and milk, and beat until incorporated. Stir in the flour, baking powder, and cinnamon.

Pour the cake batter on top of the caramel and apple layer in the cake pan.

Bake for 45 minutes. Let cool for 10 minutes. Invert onto a plate and tap the top until the cake comes out onto the plate. Sprinkle with sea salt and serve with vanilla ice cream.