Place the cranberries, water, and cinnamon sticks in a medium saucepan. Heat to boiling. Reduce heat to low. Cover and simmer for 5 minutes, stirring, until the cranberries pop.
Remove from heat, stir in the marmalade, and cool. Add sugar if the sauce is too tart. (This can be made up to 4 days ahead.) Cover and refrigerate. Serve at room temperature.