In a cocktail shaker, combine all ingredients with ice. Shake well and strain into a martini glass. Garnish with lime wedge.
For the ginger syrup:
In a medium saucepan over high heat, combine sugar, ginger and water and bring to a boil. Reduce heat and simmer until syrupy and reduced by half, about 40 to 45 minutes. Strain ginger pieces out and reserve syrup.