Classic pumpkin pie fillings contain a simple mixture of fresh or canned pumpkin, eggs, condensed milk, sugar and a thickener such as cornstarch. Also included is a blend of spices including cinnamon, nutmeg, cloves and powdered ginger. Other ingredients may be added and substituted.
Martha Stewart provides a traditional recipe for pumpkin pie filling. Begin by pureeing 3 cups of roasted or canned pumpkin in food processor. Transfer to a bowl and add the following ingredients: 6 large eggs, 1 tablespoon heavy cream, 1 1/2 cup light-brown sugar, 2 tablespoons cornstarch, 1 teaspoon salt, 1 1/2 teaspoons of both cinnamon and ground ginger, 1 teaspoon vanilla extract, 1/4 teaspoon ground (or freshly grated) nutmeg, and three cups of evaporated milk. Whisk until the mixture is combined and then pour everything into a pre-baked pie crust. At 350 degrees, the filling should take about 35 to 40 minutes to bake.
A twist on this basic recipe is available on Epicurous.com. The recipe calls for the addition of 1/2 cup sour cream and 1/4 cup apricot preserves, while no condensed milk is included. The sour cream and preserves should be mixed with the following: 2 cups pureed pumpkin, 3 large eggs, 3/4 cup heavy cream, 3/4 cup sugar, 1 tablespoon light-brown sugar, 1 tablespoon cornstarch, 1/4 teaspoon salt, 2 teaspoons cinnamon, 3/4 teaspoon ground (or grated) ginger. Pour the mixture into a pre-baked crust. Bake for 55 minutes at 325 degrees.
As a long-term mainstay of the American table, however, pumpkin pie has taken many different forms. One recipe recounted on History.com dates from the 1600s and includes no crust. Rather spices and sweetened milk are poured directly into a hollowed pumpkin, which is then baked on an open fire. No measurements are included, but the method demonstrates the great variability of pumpkin pie recipes.