Let all ingredients warm up at room temperature overnight.
Sift the flour into the mixing bowl and make a well in the middle.
The margarine, egg, sugar and the crumbled yeast come in there.
Using the hand mixer with dough hook, start processing the dough in the middle. Slowly pour in the warm milk to achieve a smooth, tear-resistant dough. Cover and place in a warm place, let rise until it has doubled.
For the filling:
Mix the egg whites with a little salt and vanilla sugar until foamy, add the ground almonds, sugar and rum. Chop the soft apples on a grater without stirring in the core.
Knead with your hands, divide the dough in half. Roll out one half and separate it into 3 equal parts.
Spread a tablespoon full of the filling on each part and roll up from the outside in, then braid the three parts into a plait, place on the baking sheet with the baking foil. Make a recess with the rolling pin and brush with egg yolk.
Prepare the second braid in exactly the same way and place it on top of the indentation and brush with egg yolk
Bake in a preheated oven at 200 degrees for 25-30 minutes.