1 1/2oz light rum
1/2oz triple sec
1 T. fresh lime juice
1 tsp. maraschino liqueur or kirsch
Sparkling water to taste
Garnish: maraschino cherry

Shake all ingredients except sparkling water in a cocktail shaker with 1 C. ice cubes, then strain into a tall glass filled with ice cubes. Add sparkling water and stir.