½c.good-quality bittersweet chocolatein 1” pieces or smaller (my favorite is 70-percent-cacao chocolate)
For the whipped topping:
1 ½c.heavy cream
2 Tbsp.Powdered sugar or more, to taste
Instructions
To make the crust:
Combine cookie crumbs and melted butter in a bowl. Mix thoroughly with a fork until all the crumbs are moist with the butter.
Press the crumb mixture firmly into a 9-inch pie pan. Chill for 15-20 minutes.
Preheat the oven to 350. Take the crust out of the refrigerator. Bake at 350 for 8 minutes. Cool.
To make the filling:
In a medium saucepan, combine the sugar, cornstarch, flour, cocoa and salt. Whisk in a little of the milk or half-and-half, mixing the liquid and dry ingredients until you're sure they're fully combined, with no lumps. Whisk in the rest of the milk and half-and-half. Whisk in the egg yolks and the vanilla.
Over medium-high heat, cook the pie filling until it thickens and comes to a boil, whisking constantly. Turn the heat down to medium and cook for about two minutes, taking special care to whisk the bottom and sides of the pan constantly.
Remove the custard from the heat. Stir in the butter and the chocolate pieces. After a minute or so, mix to blend.
Pour the filling into a bowl. Spread plastic wrap directly onto the surface of the custard to keep a thick coating from forming. Put it in the refrigerator to chill thoroughly. It might take 6-8 hours to set.
If you need the custard to set more quickly, spread it onto a rimmed baking sheet and put plastic wrap onto the top of the custard. When it's cooled, you can transfer it to a bowl, or go straight to filling the pie with it (just stir it a bit first). If you fill the pie, keep it chilled.
To make the topping:
Just before serving the pie, combine the whipping cream and the powdered sugar in the bowl of a stand mixer. I like only 2-3 tablespoons of powdered sugar in this topping; if you like a sweeter topping, add more. Whip til the cream reaches stiff peaks. Scoop generous dollops onto the pie, or pipe it decoratively on top. Garnish with dark chocolate shavings or a sprinkle of cocoa.
Notes
This pie can also be made with a pastry crust instead of a chocolate-cookie-crumb crust. Just prepare a single batch of pie dough and blind-bake it.