Make the dough by mixing the flour, milk, unsalted butter, and sugar in a bowl. Use the dough hook to mix the dough until it is no longer attached to the bowl.
Cover the bowl with flour, and let it rest for 40 minutes at room temperature. Turn it onto a floured surface. Now Use a rolling pin to make a rectangle out of the butter.
Make a rectangle from the dough, then place the butter in the middle. Fold the dough like an envelope. Make sure you wrap the butter completely. After this, Roll the dough out using a rolling pin into a rectangle measuring 20cm x 50cm. The dough should be folded in thirds along its length, similar to a business letter.
This completes the “tour”. Rotate the dough 90 degrees so the folded edge is to your left and the dough facing you. Continue rolling the dough and placing it in the fridge. After at least 30 minutes, cover the dough and leave it in there. The dough will continue to be “toured” 2 more times.
Roll the pastry into a rectangle, and then cut out bands measuring 10cm x 20cm x 5mm thick. Then, place the chocolate bar on top of the pastry and roll it. Place them on a buttered baking sheet, making sure that the joint is under the roll. Gently flatten them with your hand. Allow resting at room temperature for an additional 35/40 minutes. Bake in the oven at 180C for 25-30 minutes or until golden brown. Allow cooling before you serve it with a cup of fresh coffee.