Chocolate Cream Pie

Chocolate Cream Pie
recipe from The America's Test Kitchen Family Cookbook

Filling:
2 1/2 cups half-and-half
1/3 cup sugar
pinch salt
6 large egg yolks
2 Tb. cornstarch
6 Tb. (3/4 stick) unsalted butter, cut into 1/4-inch pieces
6 ounces semisweet or bittersweet chocolate, chopped fine
1 ounces unsweetened chocolate, chopped fine
1 tsp. vanilla

1 prepare Oreo cookie crumb crust

Topping:
1 1/2 cups heavy cream, chilled
2 Tb. sugar
1/2 teaspoon vanilla extract

1. Prepare the filling by bringing the half-and-half, half of the sugar, and the salt to a simmer in a medium saucepan over medium-high heat, stirring occasionally.
2. Meanwhile, in a separate bowl, whisk the egg yolks, remaining sugar, and cornstarch together until smooth.
3. Slowly whisk about 1 cup of the hot half-and-half mixture into the egg yolk mixture (this tempers the yolks so the eggs don't curdle/cook when added to the hot mixture, so make sure not to add all of the half-and-half at once). Then, slowly add the tempered yolk mixture to the remaining half-and-half (still on the burner), whisking continually. Reduce heat to medium. Whisking constantly,k return mixture to a simmer and cook until thickened and a few bubles burst on the surface, about 30 seconds. Remove from heat and whisk in the butter, then the chocolates, then the vanilla, whisking continually until smooth.
4. Pour the warm filling into the crust. Press a sheet of plastic wrap onto the surface of the filling (to prevent skin from forming on surface of pie as it cools) and refrigerate until filling is cold and firm, at least 3 hours.
5. Prepare the topping just before serving. Whip the cream, sugar, and vanilla together in a chilled bowl until soft peaks form. Spread over the top of the pie and serve immediately.