To make the syrup, start by cutting the vanilla bean in half width-wise, then length-wise. Scrape out the vanilla seeds and reserve. Place the vanilla bean segments in a small pot along with cardamon, allspice, clove and cinnamon, and warm over medium heat until fragrant (1 - 2 minutes). Add the sugar plus 2 tablespoons of water, stirring to combine. Let the sugar cook, stirring frequently, until it starts to caramelize (about 2 minutes)*. Stir in the rest of the water (1 cup minus 2 tablespoons), bring to a boil, and then take the syrup off the heat. Stir in the reserved vanilla seeds, cover and let cool completely. Strain into a clean jar, and reserve the strained spices.