Blackberry lime rickeys

2 cups blackberries, divided
3/4 cup sugar
1/2 cup fresh lime juice
1 cup gin
Ice cubes
1 liter sparkling water
6 to 12 thin lime slices

1) In a blender, whirl 1 1/2 cups blackberries, the sugar, and lime juice until smooth. Rub through a fine-mesh sieve into a pitcher to extract juices. Stir in gin.
2. Fill each of 6 glasses halfway with ice. Pour gin mixture into glasses and fill with sparkling water. Garnish with remaining 1/2 blackberries and the lime slices.

Date night beverage of choice