Begin by finely chopping the vegan dark chocolate and set it aside in a bowl.
In a saucepan, warm the coconut milk but avoid letting it boil.
Add the fresh mint leaves to the coconut milk and let it simmer for about 5 minutes to infuse the minty flavor.
In a separate bowl, whisk together the cornstarch and a bit of coconut milk until smooth.
Gradually add the cornstarch mixture to the saucepan, whisking constantly to avoid lumps.
Stir in the agave syrup, vanilla extract, and a pinch of salt.
Continue cooking until the mixture thickens slightly, resembling a custard-like consistency.
Remove the saucepan from the heat and add in the chopped chocolate.
Stir until the chocolate has fully melted and the mixture is smooth.
Pour the mixture into individual serving dishes and refrigerate for at least 2 hours, or until set.