Preheat the oven to 180 °C. Cut an apple with skin into pieces and remove the core. Stew the diced apple with a glass of water to make applesauce. Melt the butter and mix with the nut flour, sugar and egg. Crush the stewed apple with a fork and mix into the dough. Line a baking dish with baking paper and pour in the dough. Slice the second apple and arrange it in a tile fashion on top of the cake. Sprinkle some more sugar over the cake and pour 2 to 3 more tablespoons of melted butter over it. Place in the oven for 15 to 20 minutes.

TIP: NUT FLOURS
These days you can find different kinds of nut flours. Hazelnut flour I particularly like. Actually, it's not a flour or powder, it's just ground nuts. You can also easily make this yourself from your favorite nuts.

TIP: SMEUÏG
I often get the comment that the apple cake stays too moist. It's meant to stay moist, otherwise I wouldn't put applesauce in it anyway! This just keeps the cake moist. I.e. you won't get this apple cake dry.

A few more tips:
- Stew the diced apple with a glass of water > adding water makes the stewing process go faster and the apple does not burn, the water evaporates completely. You can also add some butter if necessary.
- Small form (20 cm) = less time in the oven, more quantities= longer in the oven.
- Every oven is different (I obviously have a powerful oven).
- Important: let the apple cake cool, when it cools it stiffens, but it never gets dry.