Ingredients
1/2 pint (1 cup) blackberries
6 ounces (3/4 cup) sweet red vermouth, preferably Cinzano Rosso
2 tablespoons superfine sugar
1 bottle (750 milliliters) Prosecco, chilled
Preparation
Gently stir together blackberries, vermouth, and sugar in a bowl. Let stand, stirring occasionally, until blackberries release juices and sugar dissolves, about 1 hour.
Spoon 2 tablespoons of the blackberry juice and 4 blackberries into each of 6 Champagne flutes. Top each with Prosecco.