Place a coup or martini glass in the freezer for a couple of minutes to chill.
Pour all the liquids in to a cocktail shaker.
Take out the chilled glass and have ready.
Fill the cocktail shaker with ice.
Cover the shaker with the lid and shake vigorously for several minutes, until the cocktail is ice cold.
Strain into the chilled glass and serve immediately, garnished with the optional candied cranberries.