Instructions

• Whisk the sugar, cocoa powder, salt, and cornstarch together in a medium saucepan. 
• Separate the yolks in a bowl and whisk them until they're smooth. 
• Whisk in 1 cup of the milk into the egg yolks and whisk until the mixture is uniform in color with no bits of brighter yolk. 
• Add the egg/milk mixture along with the rest of the milk to the saucepan and whisk it until the dry ingredients are thoroughly incorporated. 
• Bring the mixture to a simmer over medium heat while gently whisking. 
• Once the pudding begins to simmer and thicken, turn the heat down to low and continue to whisk for another 30-60 seconds until you like the look of the thickness. 
• Remove the pan from the heat and stir in the chocolate chips and butter until they are melted. 
• Stir in the vanilla. 
• Add the pudding to a bowl or ramekins and cover with plastic wrap to prevent it from skinning over. 
• Refrigerate for 4 hours or overnight until chilled before serving.