2 oz column still lightly aged Cuban rum½ oz lime juice½ oz rich simple syrup (2:1)¼ oz pink grapefruit juice1 tsp maraschino liqueur
instructions :

Add all ingredients to a shaking tin, add ice and shake until chilled.

For the original recipe by Constantino Ribalaigua :

  • 2 oz white Cuban rum
  • ½ oz lime juice
  • 1 tbsp white sugar
  • 1 tsp grapefruit juice
  • 1 tsp maraschino liqueur
  • 1½ cups (12 onces / 210g) crushed ice

Dissolve sugar in lime, then place all the ingredients in a blender for at least 20 seconds. Pour unstrained into a chilled cocktail glass.

source :
Jeffrey Morgenthaler, The Bar Book, adapted from Constantino Ribalaigua Vert, La Florida (Havana)