In a medium saucepan combine Stevia In The Raw®, water, and lemon zest. Bring to a boil, then take off the heat, cover, and let steep for 30 minutes. Strain and stir in lemon juice. Cover and chill until cold.
Transfer sorbet base to an ice cream maker and freeze following manufacturer’s instructions. Keep frozen and covered until ready to use.
To each of 4 tall glasses add ¼ cup cranberry juice and 1 packet of Stevia In The Raw® or 2 teaspoons of the Stevia In The Raw® Bakers Bag. Stir to dissolve stevia. Fill each glass with 1 cup club soda. Top each glass with a scoop of sorbet and ¼ cup blueberries. Serve immediately.