Knead all the ingredients until a raw texture is obtained and then leave to rest for at least 3 hours in a refrigerator. Roll out the dough, place the butter in the centre (at a temperature between 10 and 15° C) and fold the dough over on itself so that the butter mixture is completely enveloped. Roll out the dough and fold it over on itself in 4 layers; put in a refrigerator for 15 minutes. Repeat the rolling out and folding procedure for a total of two folds of four layers, then leave to rest for another 15 minutes in a refrigerator. Finally, roll out again to a thickness of 4-5 millimetres, cut into triangles, roll them up tightly, place on baking sheets and put in a rising room at 24°C max. with relative humidity of about 70%. Bake at 180-200°C for 17-20 minutes.