Line two 8x4x2-inch loaf pans with foil, extend foil over pan edges; set aside. Spoon 1 pint of raspberry sorbet in each prepared pan; spread evenly. Cover and freeze 1 to 2 hours or until firm. One-half hour before spreading second layer, allow vanilla ice cream to soften 30 minutes in refrigerator. Spoon 1 pint softened vanilla ice cream on raspberry sorbet in each pan. Cover; freeze 4 hours or overnight until ice cream is firm. Place serving platter in freezer.
To serve, remove ice cream loaves from pans, using foil to lift. Peel back foil and slice each loaf in 8 slices. Place slices on frozen serving platter. Serve with Hibiscus Syrup. Or scatter the additional blueberries over slices. Makes 16 servings.
In a large saucepan combine water and sugar. Bring to boiling, stirring to dissolve sugar. Add hibiscus flowers or Red Zinger herb tea bags. Reduce heat. If using flowers, boil gently for 40 to 50 minutes or until syrup is reduced to 3-1/2 cups. If using tea bags, boil gently for 5 minutes. Remove tea bags with a slotted spoon. Continue boiling gently until tea mixture is reduced to 2-1/2 cups. If using flowers, cool mixture 15 minutes; strain and discard flowers. Cover syrup and cool completely (syrup will thicken as it cools). Whisk 1 cinnamon into syrup. Add blueberries. Makes 4-1/2 cups syrup.