1 Whisk Together The Sugar, Cocoa Powder, Cornstarch, And Salt In A Heavy 2-Quart Saucepan. Gradually Whisk In The Milk. Bring To A Boil, Whisking Constantly, And Boil, Whisking, Until Pudding Is Thick, About 3 To 5 Minutes. Remove From Heat. 2 Immediately Beat The Egg Lightly In A Medium, Heat-Proof Bowl, Such As A Hard Plastic Or Ceramic Mixing Bowl. Very Gradually Add The Hot Chocolate Mixture To The Egg, Whisking Constantly. Whisk In The Chocolate Chips Until They Are Melted And The Mixture Is Smooth. 3 Pour The Pudding Into The Ramekins Or Cups. If You Want, Cover The Surface Of Each Of The Pudding Cups With Some Cut Out Wax Paper To Prevent A Skin From Forming On The Top Of The Pudding. Refrigerate, Covered, Until Cold, At Least 2 Hours. Optional: Serve With Whipped Cream.