Pit the cherries with a cherry pitter. Place in a large bowl. Add the sugar, vanilla extract, and star anise. Stir well. Cover with a kitchen cloth. Let sit for 20-25 hours.
Strain the cherries and reserve the liquid. Pour the liquid into a large heavy-bottomed pot. Add the water and the star anise that was already in the cherry bowl. Bring to a boil, lower the heat to medium-low and simmer the syrup for about 15 minutes. The syrup should not thicken too much.
Add the cherries and simmer on low heat for another 5 minutes or until the cherries are softer. The syrup should not be too thick, it should remain pourable. Remove the foam and the star anise from the pot.
Divide the cherries into sterilized jars and pour the liquid over the fruit, they should be completely covered. Seal well.
Let cool and keep in a dark cool place. They will keep for at least 3 months. You could can the jars, if desired, they will keep even longer. Once opened, keep refrigerated and eat within 4-5 days.
Video
Notes
Alternative spices: cinnamon stick, cloves (not more than 2), all-spice berries, cardamom pods.