Add coconut milk and sugar (or sweetener) to a sauce pan and whisk to combine.
Place over a medium-high heat and bring to a boil. Let boil about 5-7 minutes - whisk often until the sugar dissolves.
Reduce to a medium heat to simmer and let cook about 45 minutes - 1 hour until thickened.
Remove from heat and let cool until cool enough to store in an airtight container or jar. Milk will thicken more when chilled.
