Place all of the ingredients together in a cocktail shaker with plenty of ice and shake well to mix and chill.
Strain it into a glass filled with a little ice, pressing the mint to get as much flavor from it as you can. Note a smash is often served over plenty crushed ice so serve as you prefer.
Notes
An optional adaptation is to use ½ oz ginger syrup plus ½ oz Domaine du Canton (ginger liqueur). Slightly stronger and with a little more ginger kick.You could also add a little soda water to make this a slightly longer drink.