Chef Dennis Pitchford demonstrates his method for making this classic cocktail, which originated in Cuba. He calls it his In the black-berry mojito. He starts by putting half of a dozen mint leaves and five or six blackberries in a glass; then he adds some simple syrup and crushes this all together to release the juices. He then adds some light rum, some creme de cassis, and fresh squeezed lime juice. Finally he puts in some ice cubes and club soda, and gives it a good stir. He garnishes it with a sprig of mint and a fresh Blackberry for a light, refreshing cocktail.