In a medium saucepan, combine cranberries, water and maple syrup. Bring mixture to a boil over medium-high heat, then reduce heat to medium low and cook, stirring occasionally, until the cranberries have popped and the mixture has thickened. (5-7 minutes.)
Remove pot from heat and stir in orange zest. (If desired, add cinnamon.)
Sauce will continue to thicken as it cools. Pour into a decorative bowl, cover, and place in refrigerator for at least 4 hours before serving.
Honey or agave nectar can be used in place of maple syrup.