Half recipe pie dough
For the filling:
2 tablespoons unsalted butter
8 ounces semisweet chocolate, chopped
1 teaspoon vanilla extract
⅔ cup granulated sugar
3 tablespoons cornstarch
2 tablespoons unsweetened cocoa powder
1 teaspoon espresso powder, optional
⅛ teaspoon salt
3 large egg yolks
1 cup heavy cream, divided
2 cups milk
For the topping:
1 cup heavy cream
¼ cup confectioners’ sugar
½ teaspoon vanilla extract
Start by blind baking the pie crust. Heat oven to 400º. Roll the dough on a lightly floured surface into a 13-inch circle. Transfer it to a 9-inch pie pan and trim the edges so that they’re about an inch bigger than the pan. Tuck the edges up and under, then flute them if desired. Freeze the pie dough for 30 minutes to help retain its shape.
Line the crust with parchment paper and fill with dry beans or pie weights. Bake the crust for 20 minutes, then remove from oven and gently remove the parchment and beans or weights. Return to the oven and continue baking another 10-20 minutes, or until the crust is golden all over. If the edges start to brown too quickly, cover them with foil. Remove from oven and allow the crust to cool completely before filling.
While the crust is baking, start working on the filling. Place the chocolate, butter and vanilla in a 2-quart mixing bowl and set aside.
Whisk together the sugar, cornstarch, cocoa, espresso powder and salt in a medium saucepan. Whisk in ¼ cup of cold heavy cream and continue whisking until the mixture is smooth. Repeat with another ¼ cup of cream, then whisk in the egg yolks.
Place the saucepan over medium heat and gradually whisk in remaining cream and milk. Bring the mixture to a boil, whisking constantly. Boil for 1 minute, then pour the hot mixture over the chocolate and butter.
Whisk or stir until the mixture is smooth, then pass the custard through a fine mesh strainer to remove any lumps or pieces of cooked egg.
Place the mixture in a large, shallow bowl and place plastic wrap directly on the surface to prevent a skin from forming. Refrigerate until the mixture is thoroughly chilled. When the mixture is chilled, use a rubber spatula to scrape it into the cooled pie crust. Level the top with an offset spatula.
To make the whipped cream, place the chilled cream in a mixing bowl fitted with the whisk attachment. Whisk until soft peaks form. Add the sugar and vanilla and continue mixing until medium peaks form. Spoon or pipe the whipped cream onto the pie.
If not serving immediately, the cream can be chilled separately and piped onto the pie just before serving.