Raspberry-Rhubarb Bellini Smoothie with Blueberries (Virgin...or not so Virgin).

Bahan-bahan (4 porsi)

• 4 stalks rhubarb (chopped)
• 1 1/3 cup sugar
• 2 cups water
• 1 sprig fresh mint (chopped)
• 12 ounces fresh or thawed frozen raspberries (plus more for garnishing)
• 1/3 cup rhubarb simple syrup
• 1 cup frozen blueberries (divided)
• 4 ounce to 6 bottles sparkling water (Prosecco, or other sparkling wine, chilled, 12)
• 6 ounces fresh blueberries
• fresh mint (for garnish)