In the large bowl of the electric mixer, place the yeast and water. Stand five minutes. Blend in the evaporated milk, sugar, salt and melted butter. Add eggs and then sifted flour. Beat at low speed until blended, then turn on to a floured board and knead until smooth on the outside. Place in a lightly oiled bowl, turn dough once, cover with a damp cloth and set in a warm place until double in bluk, about an hour.