This stuff is awesome.
1 c coconut sugar
2/3 c agave nectar
1/4 c butter
1/3 c water + 1/3 c canned coconut milk
1 tsp vanilla extract
1/8 tsp salt
Combine coconut sugar, agave, and butter in a medium saucepan. Stir over medium heat until sugar dissolves and comes to a rolling boil. Allow it to boil without stirring for one minute; remove from heat and cool. In a glass measuring cup, combine water and coconut milk, vanilla, soda, and salt. Gradually stir this into the slightly-cooled sauce until smooth and combined. Drizzle some over ice cream or popcorn.
Pour the sauce into a large jar, cover, and keep in the refrigerator. It will thicken as it cools. If it thickens too much, gently warm the jar in a pot of water on the stove.
I can't remember where I originally found this recipe, but it has been adapted.