Fill a shaker ¾ full with ice. Add rum, fresh squeezed juice, and syrup. Shake vigorously for about 30 seconds. Strain into a cocktail glass.
Bay Leaf and Juniper Syrup
In a small saucepan, combine sugar, water, bay leaves, and juniper berries. Stir to dissolve sugar and bring to a boil over mediumhigh heat. Once the mixture boils, reduce the heat and allow to simmer about 5 minutes. It should thicken a little.
Remove the syrup from heat and let steep 15 to 20 minutes. Strain the syrup into a clean container with a lid. Refrigerate until ready to use for up to 1 week.