In a medium saucepan set over medium heat, whisk together the sugar, cocoa powder, salt, cornstarch, and milk.
½ cup granulated sugar, ¼ cup unsweetened cocoa powder, 3 tablespoons cornstarch, ⅛ teaspoon kosher salt, 2¾ cup milk
Constantly stir the ingredients together until they begin to boil, about 5 minutes. The chocolate should look like a thick hot cocoa.
Once it begins to boil, the mixture will start to slowly begin to thicken. Allow it to lightly boil for about 30 seconds, then turn the heat off and stir in the butter and vanilla.
3 tablespoons unsalted butter, 1 teaspoon pure vanilla extract
Continue stirring until the butter has melted into the chocolate.
Remove from heat and pour into individual bowls. Serve immediately, or cover each dish or bowl with plastic wrap gently touching the tops of the pudding, so a coating will not form on the top of the pudding.
Let the pudding set in the refrigerator for 2-3 hours before removing the plastic wrap and serving topped with whipped cream, sprinkles, and fresh fruit, if desired.
whipped cream, sprinkles, fresh fruit