Scrape out the pith of the vanilla beans. Place heavy cream and milk in a pot. Add vanilla and stir over medium temperature, bring to a boil. Let cool after.
Mix egg yolks with powdered sugar until very light and fluffy. Sift in starch. Add to cream-milk-mixture, stirring constantly and let come to a boil again.
For the tart
Sift flour onto a working area. Make a hole in the centre and add egg, 100 grams of the sugar, baking powder and baking soda. Quickly knead into a smooth dough. Wrap it in wrapping foil and refrigerate for 30 minutes.
Wash raisins and let drain water. In a small bowl drizzle with rum and allow to infuse for 10 to 15 minutes.
For the filling, roughly chop almonds and hazelnuts. Mix with heavy cream, vanilla extract, jam, raisins and marzipan.
Preheat oven to 360 degrees.
On a floured working area place dough. Sprinkle with flour, so it won't stick to the surface. Roll out as much as it fits onto a 10'' springform-pan. Place dough, press with your fingers and push it up the mold edge, about 3 cm high.
Wash apples and peel them. Get rid of the core with a apple corer. Place apples onto the dough. Fill in with marzipan-mixture.
Pour in vanilla custard.
Bake for 70 minutes at 360 degrees.
Remove tart from the oven and let sit for 24 hours for the custard to harden before serving.