Remove giblets and neck from turkey; set aside. Rinse turkey thoroughly with cold water; pat dry. Cover and refrigerate while preparing dressing.
Stuff Sausage-Cornbread Dressing into cavity of turkey; close with skewers. Tie ends of legs to tail with string or tuck them under band of skin at tail. Lift wingtips up and over back, tucking under bird securely.
Brush entire bird with melted butter; sprinkle with salt and pepper. Rub flour over surface of turkey. Place breast side up on a rack in a roasting pan; pour 2 cups water in bottom of pan. Bake at 450° for 30 minutes; reduce heat to 325° and bake 3 hours. Cut the string or band of skin holding the drumstick ends to the tail. Continue baking an additional 30 minutes to 1 hour or until drumsticks are easy to move. If turkey gets too brown, cover lightly with aluminum foil.
Transfer turkey to platter. Let stand at least 15 minutes before carving. Serve with cranberry sauce, if desired.