In a food processor, add 3 tbsp. dry hibiscus flowers. Process into a fine powder. Pour powder into a small mesh strainer and sprinkle onto a plate.
Run a freshly cut lemon wedge over the side, and over the rim of a coup glass. This is how the powder will stick. Roll just the wet side of the coup glass in the powdered hibiscus.
Sprinkle another plate with powdered sugar. Dip just the rim of the glass into the powdered sugar to coat the very top.
For the Cocktail
In a cocktail shaker with ice, add 3 oz. of prosecco, ¼ oz.spiced hibiscus syrup, ½ oz. St. Germain and ¼ oz. fresh lemon juice. Gently stir, and pour into garnished glasses.
Notes
Before your cocktail party, prepare your glasses with powdered hibiscus and powdered sugar, and pre-mix the St. Germain, lemon and spiced hibiscus syrup. That way, when it’s time to serve, simply add 1 oz. of your mixer to 3 oz. of prosecco in a cocktail shaker (for 1 cocktail), gently stir with ice, pour and serve. You can even pour the champagne in the glasses, then add the hibiscus mixer for a different look.