If desired, wet the rim of a tall martini glass, then dip in the coarse brown sugar crystals. In a cocktail shaker, combine the vodka, triple sec, and juice with crushed ice. Shake well for 30 seconds, then strain into the prepared martini glass. Gently add the creme de cassis, allowing to fall to the bottom of the glass. Garnish with a candied orange slice, if desired, and serve.
Yield: 1 cocktail