Set out six small heat-safe cups or ramekins. Stir the entire can of coconut milk until its cream and liquid are evenly combined.

In a medium heavy-bottomed saucepan, whisk together the sugar, cocoa, cornstarch, and salt. Gradually whisk in half the almond milk to make a smooth paste. Add the remaining almond milk and all the coconut milk.

Place over medium heat. Stir continuously, scraping the bottom and corners, until the mixture thickens and bubbles break across the surface. This usually takes about 7-9 minutes, depending on the pan and burner.

Adjust the heat to maintain steady bubbling and continue stirring for 1 minute. Remove from the heat. Do not stop at the first hint of thickening or boil for several extra minutes.

Stir in the vanilla. For a smoother pudding, pass through a fine-mesh strainer while hot if needed. Divide evenly among the cups; each is roughly a scant 1/2 cup.

To reduce a surface skin, use food-safe wrap suitable for warm-food contact, following its package instructions. Refrigerate the small portions promptly without waiting for them to cool completely on the counter. Chill for at least 4 hours, until cold throughout and set.

Add fresh berries just before serving. Gently stir a chilled portion if you prefer a softer texture.