From: Serious Eats
Ingredients
10 star anise pods
1 tablespoon licorice root
1/2 teaspoon fennel seeds
1/4 teaspoon whole coriander seeds
1/2 teaspoon anise seeds
1 1/2 cups vodka
1/3 cup sugar
1/2 cup water
Procedures
With a mortar and pestle, roughly break up anise, licorice root, fennel, coriander, and anise.
Add them to a sealable glass jar along with vodka. Seal and shake, then let steep for 5 days at room temperature away from direct sunlight, shaking occasionally.
Boil sugar and water together until integrated into a light syrup, about 7 minutes.
While the syrup is cooling, strain the spices out of the vodka mixture through a cheesecloth lining a fine-mesh strainer. Strain twice if necessary to remove all sediment.
Once syrup is cool add it to the strained vodka infusion and shake.
Let rest for 4 days or more before use. Store at room temperature for up to 4 months.