Cut a lid off the top of the apple. Hollow out apples, leaving a 2 cm rim for hold. Grease a baking dish and place the apples in it.
Melt the butter in a small saucepan and lightly toast the flaked almonds in it. Add the sugar, cinnamon, honey and the walnuts and let them become translucent. Let the whole thing cool down a bit before adding the crushed marzipan. Knead everything well and fill the apples with it.
Squeeze out the orange juice and add the lemon juice to the saucepan in which the filling was and heat briefly. Spread the juice over the apple filling and place the apples in the preheated oven for 30 minutes at 200 degrees. After 20 minutes, put the lid on the apples and cook at the same time.
In the meantime, make the vanilla sauce. To do this, mix 100 ml milk with cornstarch. Heat the rest of the milk in a saucepan with sugar and salt. Scrape the pulp from the vanilla pod and place in the pan with the empty pod.
Bring everything to the boil once and add the milk-cornstarch mixture while stirring constantly and simmer for about 1 minute.
Then take it off the stove and remove the empty pod. Now stir the egg yolks in a mixing bowl with a whisk and add 3-4 tablespoons of the hot vanilla sauce while stirring. Then add the egg yolk mixture to the vanilla sauce while stirring.