Mash berries or whirl in blender at low speed until coarsely chopped. Place berries into a large bowl and mix with sugar and marshmallow fluff. Freeze evaporated milk until mushy and then whip with an electric mixer until very thick. Fold whipped cream into blueberry mixture. Pile mixture into pie shell, piling it high. Freeze until hard. Cover and freeze until needed. Garnish with whipped cream and fresh blueberries. Yield: 1 9-inch pie.