Juice fresh limes to yield 0.75 oz of lime juice (about half a lime). Measure the Jamaican dark rum, aged/gold rum, orange curaçao, orgeat, and simple syrup into a jigger or measuring cup.

Combine and shake

Add the measured rums, lime juice, orange curaçao, orgeat, and simple syrup to a cocktail shaker filled with ice (about 4-6 large cubes). Secure the lid and shake vigorously for 10-12 seconds until well chilled and slightly diluted.

Prepare glass

Fill a double old-fashioned glass or tiki goblet with crushed ice, leaving room at the top for a float and garnish.

Strain

Double-strain the shaken mixture over the crushed ice using a Hawthorne or fine strainer so the drink sits neatly atop the ice without large shards from the shaker.

Optional demerara float

If using, gently pour 0.25 oz of dark demerara or aged rum over the back of a spoon held just above the drink to create a floating layer of rum and aroma.

Garnish & serve

Slap the mint sprig between your palms once to release aromatics, then tuck it into the top of the crushed ice along with a lime wheel or half-wheel. Serve with a short straw and enjoy immediately.