Combine flour, salt, sugar, yeast and water and knead, either manually or with the stand mixer and dough hook in 5 minutes to form a supple dough. Then work the softened butter into the dough in 4 portions and knead for a few more minutes until you have a soft, velvety and supple dough.
500 g flour, 1 sachet yeast, 70 g sugar, 3 g salt, 150 g soft butter, 250 ml lukewarm water
Form a ball of the dough and place the dough in the lightly oiled bowl. Cover the bowl with plastic wrap or a lid and let rise in a warm place (ideally 27° C) for about 45 minutes, or until the dough has doubled in volume. In the meantime, prepare the fillings, streusel and syrup.
After 45 minutes of rising, deposit the dough on a floured work surface and divide it into two portions. Roll out one piece of dough into a square of about 23 x 23 cm (the size of your baking tin - 2 cm). Flour your dough again if necessary to prevent sticking to your work surface or rolling pin.
Grease both baking tins. If desired, also place a piece of baking paper in the baking tin.
Spread the dough sheet with one of the fillings. Keep about 1 cm. of the dough free on all sides.
Now roll the piece up into a roll. Repeat this process with the second piece of dough and the other filling.
Now cut both dough rolls in half lengthwise with a really sharp knife.
Place the halves cut side up and lay one half over the other so that a large X forms.
Now braid the halves together. Pinch the dough ends together.
Place the braid in a greased baking pan. Repeat this process with the other two dough halves.
Cover both baking tins with plastic wrap or a cloth and set to proof for 20 minutes in a warm place (ideally 27° C).
Preheat your oven to 175° C.
After 20 minutes, sprinkle both the Babka's-to-be lightly with the streusel (make sure you can still see the beautiful filling) and place in the oven.
Bake the Babka's until golden brown in about 45 minutes. Check doneness with a thermometer (at least 85° C).
Pour the sugar syrup on and over the Babkas. Allow the Babkas to cool for about 20 minutes before carefully removing from the tin. Allow to cool further on a wire rack.