Slice the oranges into rounds. Split the vanilla bean lengthwise. Pour the juice into a crock pot or stainless steel pot, add the oranges, vanilla extract and bean, and cinnamon. Bring up to a moderate boil and hold there for at least 15 minutes. Then reduce the heat to a simmer, and continue to cook 30-45 minutes longer. Add maple syrup if necessary.

May be kept warm all day - just add more juice in small amounts each time.