Knead all the ingredients together, apart from butter, until a smooth, velvety consistency is obtained. Add the butter previously melted at low temperature. Roll up and leave to rest at room temperature (20-22°C) for about 30 minutes. Divide the dough into 70-90 gramme pieces, roll up and roll out into long loaf shapes. Leave to rise at 28-30°C with relative humidity of about 70% for 50-70 minutes. Glaze with beaten egg and bake at 190-200°C for 15-18 minutes.