1.    In a bowl, combine gelatin and 2 cups boiling water; stir until dissolved. Stir in 1-1/3 cups cold water until well combined; chill until set, about 1 hour.
2.    Meanwhile, in a saucepan, combine 3 cups of the blueberries, the sugar and 1/4 cup water. Bring mixture to a boil; cook until the berries burst, about 2 minutes; cool. Fold 3 cups uncooked blueberries into the sauce.
3.    In a blender container, place remaining 4 cups blueberries; pulse until a chunky purée forms.  Add dissolved gelatin; pulse just to combine. Pour mixture into a large bowl. 
4.    In another bowl, beat cream until soft peaks form.  Fold 1/4 of the cream into the blueberry mixture; fold in remaining cream.
5.    Spoon half of the blueberry sauce into 16 (8-ounce) glasses, dividing evenly.  Top with half the blueberry-cream mixture.  Repeat once.  Garnish with mint sprigs, if desired.

Yield : 16 portions (about 14 cups)