Peel apples and chop into pieces. Place them into the baking pan. Mix sugar, cinnamon and apple juice, pour it onto the apples and mix everything. Add the small pieces of butter. 

Bake for 16 minutes at 200°C in a fan oven. Mix once after 8 minutes.

Beat egg yolks, sugar and vanilla sugar until fluffy. Add the flour, zest the lemon and mix it in, then squeeze the lemon and mix in the juice as well.

Whisk egg whites and salt stiff. Add the sugar, briefly continue to whisk, then fold it into the egg yolk mixture and pour everything over the apples.

Bake for another 12 minutes at 200°C in a fan oven. Leave to cool for 15 minutes. Besprinkle with powdered sugar and serve. 

Recommendation: serve with a warm vanilla sauce.