Add all ingredients, except vanilla, to a saucepan. Bring to a boil, then turn down heat to medium. Simmer lightly for 10 minutes, and remove 1/3 cup of the still whole cranberries.
Simmer 10 more minutes, until thickened, stirring frequently.
Stir in the cranberries you set aside, and the vanilla. Let cool 10 minutes before serving. Can be made up to 3 days in advance of serving.