In a small mixing bowl, mix the water and cornstarch together to form a paste.

Combine the soy milk, vanilla, cocoa powder, and cornstarch mixture in a large saucepan over medium heat.

Bring the mixture to a boil, stirring frequently to avoid burning.

Keep stirring while the mixture boils until it begins to thicken.

Remove from heat and cool for 5 minutes. The pudding will continue to thicken as it cools.

Pour into a serving bowl or individual serving cups, and finish cooling the pudding in the refrigerator.

Once completely cooled, serve plain or topped with dairy-free whipped cream.