In a medium saucepan, cook raw sweet potatoes or yams in enough boiling salted water to cover for 20 to 25 minutes or until tender. Drain. Cool slightly and peel. Mash cooked or canned sweet potatoes (you should have 1-1/2 cups.) Set aside.
Preheat oven to 375F degrees.
In a large mixing bowl, combine mashed sweet potatoes, brown sugar, molasses, cinnamon, ginger, nutmeg, and salt. Add eggs and milk; mix well.
Pour sweet potato mixture into unbaked pie shell. Cover edge of pie with foil. Bake in 375F degree oven for 20 minutes. Remove the foil. Bake for 30 to 35 minutes more or until a knife, inserted halfway between the center and edge, comes out clean.
Cool on a wire rack. Cover and chill to store. Serve with sweetened whipped cream, if desired.