Add coconut milk and sugar in a medium pot. Stir the coconut milk and sugar to combine.
Bring coconut milk mixture to a gentle simmer, stirring periodically. Simmer for 35-40 minutes or until the milk thickens. Add vanilla for a boost of flavor.
Use your condensed milk immediately or store in a container with a tight-fitting lid and allow it to cool. Store it in the refrigerator for 5-7 days.