Custard pie is a pie with an egg, milk or cream, and sugar filling baked in a pastry shell until just set, giving it a smooth, faintly wobbly texture. It differs from a cream pie, which is filled with a pre-cooked, starch-thickened pudding and topped with whipped cream or meringue rather than baked as a single custard. Classic variations include pumpkin, coconut, lemon, and butterscotch custard pie, often flavored with vanilla, nutmeg, or lemon zest and served chilled or at room temperature.