In a bowl, mix 100 ml lukewarm milk, 1 yeast cube, and 1 tablespoon sugar. Dust with a little flour and let rise for 15 min. Add the remaining dough ingredients: flour, egg, remaining milk, salt, sugar, and vanilla sugar. Knead on medium speed with a dough hook for 10 min. Let rise for 60 min.
Mix the apples with cinnamon. Roll out the dough into a rectangle. Brush with the melted butter, leaving a 1 cm margin uncovered around the edges. Sprinkle the sugar on top. Spread the apples and raisins on the sugar.
Roll up the dough tightly from the long side and cut into 15 slices. Place on a baking tray lined with baking paper. Bake in a preheated oven at 175°C (350°F) for 20 min. Mix and spread the topping on the snails while still warm.