Cook cranberries in water with the vanilla bean until the cranberries are soft and begin to pop. Remove vanilla bean and set aside. Sieve the berries or run through a food processor then sieve out skins and seeds. Place back in saucepan and add sugar, juice, and vanilla bean. Cook for another five minutes. Remove from heat, add vanilla extract if you are not using a vanilla bean, and chill.
When you are ready to freeze the cranberry mixture, remove vanilla bean. The bean can be used again. Process in an ice cream maker according to manufacturer’s instructions or, freeze in a shallow pan. When mixture is frozen, run through the food processor and freeze again until about 10 minutes before serving. Allow to soften enough to scoop into individual dishes. Garnish with mint leaves.