Make the sweetened condensed coconut milk at least 2 hours before making the vegan ice cream so it'll have time to cool.
Pour the canned coconut milk into a saucepan over medium heat, stirring occasionally.
Bring the coconut milk to a boil for 5 minutes, stirring and keeping an eye on it.
Add in the agave and reduce the heat to a simmer for 25 to 30 minutes or until the coconut milk is reduced by half.
Remove from heat and let the vegan condensed milk cool down. Once it's at room temperature, transfer the condensed coconut milk to the fridge.
For the ice cream:
Scoop out the coconut milk solids into a large bowl and whip until fluffy.
Add in the vanilla extract and mix until combined.
Gently fold in the vegan sweetened condensed milk.
Pour the coconut ice cream mixture into a loaf pan, cover with plastic wrap, and freeze for at least 1 hour to thicken.
Notes
This vegan ice cream has the best consistency after you freeze it for 1 hour. But if you freeze it for a longer period, let it sit for a few minutes at room temperature to thaw before scooping.