In a large pot, whisk together the brown sugar, cocoa powder, and cornstarch. Add the soymilk and pinch of salt, 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 to medium low. Once the pudding comes to a simmer, lower the heat and continue simmering gently, whisking continually, for another few minutes until the pudding is thick.

Remove the saucepan from heat and stir in the vanilla. Serve the pudding warm, or scoop into a serving bowl or individual cups. Press a piece of plastic wrap onto the surface of the pudding (to prevent a skin from forming) and refrigerate until ready to serve.