The evening before: Put sieved flours in the bowl of a stand mixer, add beer yeast previously dissolved in milk and then sugar and eggs. Knead with the dough hook at medium speed for 5 minutes. Then increase the speed and knead for another 10-15 minutes. As soon as the dough comes off the mixer, continue kneading by hand on the work surface. Then fold the dough from the edges in towards the middle. Repeat several times to strengthen the gluten mesh. Form a ball and put it in a slightly greased bowl, cover with cling film and let rise until doubled.

Remove the cold butter from the fridge and cut it into slices about 3 mm thick. Place the butter slices close to each other on a baking paper sheet to form a rectangle of about 20×30 cm. Cover with a second baking paper sheet and press gently with the help of a rolling pin so that the butter slices become one large rectangle. Cover with baking paper and keep in the fridge until use. The butter has to remain very cold to get a flaky dough. Take the brioche dough out of the fridge and roll it out to a rectangle with a rolling pin. This rectangle should be as wide as the butter rectangle before but twice as long. Put the butter rectangle at the center of the brioche dough. Fold the two outer sides in towards the middle to close it at the center and rotate the dough by 90°. Just turn it a little by keeping the closed part vertically. Then roll out the dough with a rolling pin until it reaches a length of about 30 cm. Fold three times to form a rectangle. Wrap in cling film and let rest in the fridge for 30 minutes. Repeat this folding process two more times respecting the resting time in the fridge. Wrap the dough in cling film and keep in the fridge overnight.

The next day: Peel apples and cut them into small pieces. Cook them in a pan with a knob of butter and add cane sugar and cinnamon. Continue cooking for about ten minutes, turn off the heat and let cool completely. Remove the dough from the fridge and divide it into two equally sized halves. Roll out the first half to a rectangle and use a pastry cutter to cut out 12 smaller rectangles. Put a tablespoon of jam and a bit of the cold apple filling at the center of each rectangle. Roll out the second half and make a grid with the help of a lattice dough roller.

Then cut out another 12 rectangles of equal size to the first and cover each apple dumpling with a dough grid. Seal the edges well. Place the apple dumplings with sufficient distance from each other on a baking sheet lined with baking paper. Cover them with a dish towel and let rise for 30 minutes. Then brush the apple dumplings with the egg and milk mixture and bake in the oven at 180°C (top/bottom heat) for about 25 minutes.