Preheat your oven to 350 degrees. Stir together the crushed oreos and melted butter until well coated. Press the crust mixture into a 9 inch pie plate evenly and firmly. Bake the crust for 10 minutes, or until it looks fairly dry and set. Let the crust cool completely.

In a medium saucepan, whisk together 2/3 cup sugar, the cornstarch, cocoa powder, and salt until combined. Slowly whisk in the whole milk, heavy cream, and vanilla extract until combined. Heat the mixture over low-medium heat, whisking often.

While the milk mixture heats, in a small bowl whisk together the egg yolks and remaining 2 tbs. of sugar until they become pale. Once the milk mixture is steaming hot, ladle in about 2 cups of the milk mixture into the egg yolk mixture very slowly, whisking constantly. This is to temper the egg yolks. Then, pour the egg mixture back into the pot, and whisk everything together. Whisk constantly over low-medium heat until the mixture becomes very thick, about 5-8 minutes.

Once the mixture thickens, remove it from the heat and continue to whisk in the chopped chocolate for about 30 seconds-1 minute. If you see any lumps, push the custard through a fine mesh sieve at this point. Pour into a heat safe bowl, and cover with plastic wrap that is pressed directly on top of the custard. Chill the mixture for 1-2 hours, or until it is completely chilled through.

Once the custard is fully cooled, in a large bowl or the bowl of a stand mixer, whip the heavy cream until it has very soft peaks. Sprinkle in the instant pudding mix, and continue whipping until the cream has formed soft peaks.

In another large bowl, add in the cooled custard and stir it to loosen slightly. Add in about 1/3 of the whipped cream and fold it through the custard mixture until it is fully combined and no streaks of white remain. Then add in about another 1/3 of the whipped cream, and gently fold that in as well. Pour this mixture into the prepared pie crust and smooth it out. It's ok if you have to mound the mixture up a bit depending on the size of your pie plate. Then top the chocolate filling with the remaining whipped cream. Cover the pie and chill it for at least two hours before serving. Serve with a light dusting of cocoa powder, optionally. Enjoy!