The solution: First the crust: When baking other custard-based pies, such as pumpkin, the Cook’s test kitchen has found the best method to be prebaking the crust, adding a hot filling, and then finishing the baking in the oven. Because the crust is cooked enough to crisp, it’s less prone to absorb liquid from the filling and turning soggy. Unfortunately, this technique didn’t quite work for us this time because the custard took too long to cook. By the time it was done, the crust was overcooked. What we needed to do was to get the custard to thicken faster.
As many bakers know, cornstarch helps to prevent eggs from curdling—certainly a helpful contribution to make to a custard. But cornstarch has still other contributions to make. For one, it causes the heat to be transmitted more evenly throughout the custard; this helps to take care of the overcooked outer ring. It also, of course, thickens things. We tested different amounts of cornstarch and soon hit upon the right one. Now the pie was evenly cooked throughout, including the edges. It also had a delicate, light texture. The "eggy" problem was taken care of by an abundance of milk and cream.

RICH, SILKY CUSTARD PIE

Serves 8

For a flaky and tender pie pastry with detailed instructions on how to prebake it, see “The Secrets of Prebaking Pie Shells” in the September/October 1997 issue of Cook’s Illustrated. The prebaked pie shell can be made ahead, but it should be heated in a 375-degree oven until hot, about 5 minutes, before the custard filling is poured into it. Or, if you prefer to prebake the pie shell and make the pie in one continuous process, begin heating the milk and cream for the custard when the foil and pie weights are removed; the filling should be ready at the same time as the shell is ready to be filled. (The oven rack position and temperature for prebaking the pie shell remain the same for the filled pie.) It is a given: Your pie shell will shrink as it bakes. With minimal shrinkage, all the custard will fit into the shell, but if you experience more severe shrinkage you will have some leftover filling.

2 cups whole milk
1 cup heavy cream
3 large eggs
2/3 cup sugar
3 tablespoons cornstarch
2 teaspoons vanilla extract
1/4 teaspoon fresh grated nutmeg
1/8 teaspoon salt
1 prebaked 9-inch pie shell (see note above)

1. Adjust oven rack to lower-middle position and heat oven to 375 degrees. Heat milk and cream in medium saucepan over medium-low heat until steaming, about 6 minutes. Meanwhile, whisk together eggs, sugar, cornstarch, vanilla, nutmeg, and salt in medium bowl.

2. Heat prebaked pie shell in oven until hot, about 5 minutes. Meanwhile, whisk steaming milk and cream into egg and cornstarch mixture in slow, steady stream. Return egg and milk mixture to saucepan and cook over medium-low heat, stirring constantly with wooden spoon, scraping bottom of pan, until custard begins to thicken and forms a ridge on tip of spoon when bottom of pan is scraped and spoon is lifted, 6 to 8 minutes. (If using thermometer, stir occasionally until custard reaches 160, then constantly.) Leaving pie plate on oven rack, pour custard into hot pie shell. Bake until custard has set around edges but jiggles slightly in the center when shaken, 12 to 15 minutes. Cool to room temperature, 2 hours. Cut into wedges and serve.

LEMON CUSTARD PIE

Follow recipe for Rich, Silky Custard Pie, decreasing vanilla to 1 teaspoon, substituting 1 1/2 tablespoons grated lemon zest for the nutmeg, and whisking 1 1/2 tablespoons lemon juice into egg and cornstarch mixture.

ORANGE CUSTARD PIE

Follow recipe for Rich, Silky Custard Pie, decreasing vanilla to 1 teaspoon, substituting 1 1/2 tablespoons grated orange zest for the nutmeg, and whisking 1 1/2 tablespoons orange juice into egg and cornstarch mixture.