If you plan to cover the pie with meringue instead of whipped cream, read About Meringue.
Line a 9-inch pie pan with:
Bake the crust as directed in About Blind Baking Crusts, About Pat-in-the-Pan Crusts, or About Crumb Crusts. If topping the pie with meringue, adjust the oven temperature to 375°F if necessary.
Whisk in a medium heavy saucepan until well blended:
Gradually whisk in:
Vigorously whisk in until no yellow streaks remain:
Stirring constantly with a silicone spatula, bring to a simmer over medium heat. Remove from the heat, scrape the corners of the saucepan, and whisk until smooth. Return to the heat and, whisking constantly, bring to a sputtering simmer and cook for 1 minute. Off the heat, whisk in:
Spoon the filling into the prepared crust.
To cover the pie with meringue, proceed at once, while the filling is still hot, to prepare:
Spread the meringue over the top of the hot pie, anchoring it to the crust rim all around. Bake the pie until the meringue is browned, 15 to 20 minutes, let cool completely on a rack, and refrigerate.
To cover the pie with whipped cream, press a sheet of plastic wrap directly on the surface of the filling. Refrigerate the pie for at least 3 hours to firm the filling. Shortly before serving, remove the plastic wrap and cover the pie with: