Soak the whole duck in the large pot of boiling water. Remove it as soon as the skin changes color.
Sprinkle the inside of the duck with sugar, salt, and five-spice powder. Rub the skin of the duck with molasses. Truss the duck with string and hang in an airing place for 2 hours, or put the duck in the refrigerator overnight without any cover. This will dry the skin of the duck so that it will be crispy.
Preheat rotisserie oven to 375 degrees and bake for 45 minutes or until the skin is reddish brown.
Before serving, pour hot oil over the skin to increase the crispiness. Carve the skin and meat from the duck, and serve.