Add coconut milk and sugar to a sauce pan. Mix well and cook over high heat whisking often.
Bring to a boil and let boil for 5 to 10 minutes to thicken and whisk the whole time so nothing burns on the bottom. If you cook it 5 minutes your syrup will be thinner than if you cook it for 10 minutes.
Remove from heat and mix in vanilla and salt. Cool and store in the fridge.
The syrup will thicken as it cools and even more in the fridge.