Add the flour, powdered sugar, and salt to the bowl of a food processor, and pulse until well combined. Add in the butter and pulse 5-7 times, or until the butter is broken down into tiny pebbles.
With the motor running, add in the eggs and let the dough process until it forms together into a cohesive ball around the blade, about 1 minute.
Transfer the dough to a flour-dusted work surface.
Roll out the pie dough to an 11″ circle and line a 9” pie plate, crimp the edges as desired. Prick the bottom of the dough all over with a fork. Place the pie in the freezer while the oven preheats, at least 15 minutes.
Preheat the oven to 375ºF.
Once chilled, line the pie dough with a parchment round piece of paper and then add pie weights (or dry rice or beans or lentils), pushing pie weights to the edges.
Bake for 20 minutes, then remove from the oven and carefully remove the parchment and pie weights. Return to oven and bake for an additional 10 minutes or until the pastry is fully cooked through. Set aside until ready to use.
In a heavy-bottomed medium pot, whisk together the sugar, cornstarch, and salt. Whisk in the egg yolks and about ⅓ of the milk until smooth. Whisk in the remaining milk, then stir in the chopped chocolate.
Turn on the heat to medium. Cook the mixture, whisking constantly and occasionally using a rubber spatula to scrape up any thickened pudding in the edges of the pan, until the pudding has fully thickened and large bubbles are forming and popping, about 8 minutes.
Remove from the heat and immediately pour the pudding through a fine-mesh strainer into a bowl, using the spatula to push all the pudding through the strainer. Whisk the butter and vanilla into the pudding until fully combined.
Transfer the pudding into the prepared pie crust. Place a piece of plastic wrap on the surface of the pudding to prevent a "skin" from forming. Let cool to room temperature before chilling in the refrigerator for at least 3 hours or overnight.
To the bowl of an electric mixer fitted with a whisk attachment, add cream cheese, sugar, and vanilla. Beat until the cream cheese is smooth, about 1 minute, scraping the bowl as needed. Add the heavy cream and beat on medium speed until the cream has reached soft stiff peaks, about 2 minutes more.
Place whipped cream on top of the pie. Using an offset spatula spread the cream evenly on top of the pie. Garnish the pie with additional pieces of chopped chocolate.
Serve immediately or keep chilled until ready to serve, up to 1 day.
