In a heavy saucepan, mix together the sugar, cocoa and salt. Gradually stir in the warm water, making a smooth, runny paste.
Stirring constantly, bring to a boil over medium heat, then remove from the heat. For an especially thick and chocolaty pudding, add the chopped chocolate and stir briskly until melted.
Stir in 1 3/4 cups of the half-and-half.
Place the cornstarch in a separate bowl. Gradually add the remaining 1/4 cup of half-and-half, making a smooth paste.
Thoroughly stir the cornstarch paste into the chocolate mixture. Cook, stirring constantly, over medium heat until the mixture begins to thicken. Reduce the heat to low; stirring briskly, bring to a simmer and cook for 1 minute. Remove from heat, then stir in the vanilla.
Pour the pudding into one 3-cup bowl, or 4 or 5 (5- to 6-ounce) cups or ramekins. (If you’ll be unmolding the pudding, oil the cups first).
If you do not want a skin to form, immediately press plastic wrap directly onto the surface of the pudding. Refrigerate for at least 2 hours or up to 2 days.
Serve garnished with whipped cream and grated chocolate if desired.
Makes 4 or 5 servings.
Please Note: Nutritional values listed may vary from final results depending on actual measurements and brands used to prepare the recipe.