Preheat oven to 400 degrees. Grease a medium sized baking dish and set aside.
In a medium saucepan, combine sugar, orange juice, butter, cinnamon, nutmeg and salt. Bring to a boil, then reduce to a simmer. Cook for 10 minutes or until sauce has slightly thickened. Discard cinnamon stick.
Layer sweet potatoes in a baking dish. Pour sauce over the potatoes. Cover with aluminum foil and cook covered for 30 minutes. Remove foil and cook for 50 minutes, basting the sauce over the sweet potatoes every 15 minutes. Remove from oven and let cool before serving. Serve and enjoy!