Step 1

Combine the raspberries, sugar and 3/4 cup water in a small saucepan. Bring to a boil. Reduce the heat and simmer, uncovered, until the raspberries begin to fall apart and the sugar dissolves, about 5 minutes. Strain the liquid through a wire-mesh strainer into a glass measuring cup, pressing the solids to release the juices. Discard the solids and let the simple syrup cool completely.

Step 2

To serve, pour 2 tablespoons simple syrup in the bottom of each of 8 champagne flutes. Top with 1/3 cup grapefruit juice and about 1/3 cup sparkling rose. Top each with about 1 tablespoon vodka and garnish with raspberries and grapefruit slices.