From America's Test Kitchen Season 2: Diner Pies
Chocolate cream pies can look superb but are often gummy, gluey, overly sweet, and impossible to slice. We wanted a voluptuously creamy pie, with a well-balanced chocolate flavor somewhere between milkshake and melted candy bar, and a delicious, easy-to-slice crust. After testing every type of cookie on the market, we hit on pulverized Oreos and a bit of melted butter for the tastiest, most tender, sliceable crumb crust. We found that the secret to perfect chocolate cream pie filling was to combine two different types of chocolate for a deeper, more complex flavor. Bittersweet or semisweet chocolate provides the main thrust of flavor and intensely flavored unsweetened chocolate lends depth. One ounce of unsweetened chocolate may not seem like much, but it gives this pie great flavor. We also discovered that the custard’s texture depended upon carefully pouring the egg yolk mixture into simmering half-and-half, then whisking in butter.
Makes on 9-inch pie, serving 8 to 10
For the best chocolate flavor and texture, we recommend either Callebaut semisweet and unsweetened chocolates or Hershey's Special Dark and Hershey's unsweetened chocolates. Do not combine the yolks and sugar in advance of making the filling--the sugar will begin to denature the yolks, and the finished cream will be pitted.