Lightly muddle 8 mint leaves in the base of a cocktail shaker until bruised. Spoon them into a chilled collins glass and rub them around the inside.
Add 60ml of light gold rum, 22.5ml of fresh lime juice, 15ml of rich demerara syrup, and 2 dashes of Angostura bitters. Fill the glass two-thirds with crushed ice and swizzle.
Top with more crushed ice, churn briefly, and garnish with a lime wedge and a bouquet of mint sprigs.
