For the Christmas apple sheet cake with marzipan, quickly knead flour, butter, powdered sugar, egg yolks, salt and baking powder into a shortcrust pastry. Let rest in the refrigerator for 2 hours.
Stir vanilla pudding with 3 tablespoons apple juice and granulated sugar until smooth. Stir into boiling apple juice and simmer for one minute. Chill.
Peel, core and cut apples into small pieces, bring to a boil with white wine, vanilla flavoring, lemon juice and cinnamon powder and simmer for about 3 minutes, then stir in the pudding and bring to a boil once and let cool.
Roll the short pastry onto a baking sheet (size 30×20 cm) and spread with the cold apple mixture. Grate marzipan and mix with powdered sugar and egg until smooth, fill into a piping bag with a star-shaped nozzle and pipe over the apple mixture in a grid pattern, sprinkle with chopped nuts.
Baking temperature: 170° C
Baking time: 50 minutes