Knead all of the ingredients together to form an even dough. Leave the dough to rest at room temperature for 10 minutes. Roll out the dough with a sheeter and introduce the margarine. Perform three letter-fold sequences and leave the dough to rest for a few minutes. Laminate until a thickness of 3-4 mm is reached and shape as desired (the same dough can also be used for savoury croissants). Position on baking trays and place in a proofing cabinet at 28-30°C with 80% RH for 90-120 minutes. Glaze the surface with egg and bake in a static oven at 180°C or in a rotor oven at 160°C for 20-22 minutes.