Combine the avocado, cocoa powder, agave, plant milk, vanilla, and salt in a blender. Blend until smooth.
Spoon the avocado mousse into 4 ramekins, cover each with plastic wrap, and chill for 1 hour.
Serve cold with fresh berries.
Notes
To store: Avocado chocolate mousse can be stored in the refrigerator for up to 3 days; just be sure to wrap it tightly or store it in an airtight container.To freeze: You can freeze avocado mousse for up to 3 months. Eat it frozen or thaw it in the refrigerator before enjoying.