Preheat oven at 180°C. Beat the egg together with cream cheese and sugar. Add the grounded hazelnuts, flour, baking powder and whisk again. Pour the batter in two small baking dishes.
Peal de apple in quarters (not too thin) and push slightly the slices into the batter (the thin side of the slices pointing vertically downwards). Dust the surface with a little sugar and bake for 30 to 35 minutes.
