In a large pot, whisk together the sugar, cocoa powder, cornstarch, and pinch of salt. Add the soymilk, whisking until smooth. Bring the mixture to a simmer over medium heat, whisking continually. If mixture looks like it’s starting to scorch or burn, reduce the heat slightly. Cook the pudding, whisking continually, for 5 to 10 minutes, or until pudding is really thickened.

Remove the saucepan from heat and stir in the vanilla. Serve the pudding warm, or scoop into a bowl or small canning jars or containers and let cool. If you don’t like the chocolate skin that forms on the top of cooled pudding (I personally love it!), you can press a piece of plastic wrap onto the top of the warm pudding. Refrigerate until ready to serve.