Cream pies and custard pies are similar in that they are based on milk and eggs, but for the cook, cream pies are easier and more forgiving. That’s because their fillings are thickened with cornstarch and cooked on the stovetop, rather than in the oven, and poured into a fully baked pie shell. While delicate custards are thickened with eggs alone and lose their silky texture if overbaked, the addition of starch to a cream pie makes a filling that stands up to boiling temperatures without harm. Like custard pies, cream pies are at their best when freshly made.
Some cream and custard fillings are made with plain milk, others with evaporated milk—milk from which some of the water has been removed. Evaporated milk is sold in cans and is not refrigerated. It is lower in fat than heavy cream but has about the same consistency. Once a staple in cooking and baking, it has a rich, vaguely caramely flavor that is right in sync with old-fashioned cream and custard pies. Although its use has faded, I continue to think that in some fillings, its once-familiar taste blends well with the other ingredients.
If you are in a hurry and can’t face making a full-dress pie, keep in mind that any cream filling also makes a good, old-fashioned pudding, served on its own in bowls or glasses.
For storage, refrigerate any cream pie, or any milk- or egg-based filling or any pie with a cream or meringue topping.