- 1 3/4 cups graham-cracker crumbs (about 7 ounces)
- 1 stick (4 ounces) unsalted butter, melted
- 1/4 teaspoon cinnamon
- 3 large egg yolks
- 1/4 teaspoon cream of tartar
- Two 14-ounce cans sweetened condensed milk
- 2/3 cup Key lime juice, preferably fresh
- Preheat the oven to 350°. In a medium bowl, stir together the graham-cracker crumbs, melted butter and cinnamon. Evenly press the crumbs into a 9-inch pie plate. Bake for about 12 minutes, or until firm. Remove the crust from the oven and lower the temperature to 325°.
- In a large bowl, whisk the egg yolks with the cream of tartar until frothy. Stir in the condensed milk, then whisk in the Key lime juice until fully incorporated.
- Pour the filling into the crust and bake for about 15 minutes, or until set. Let the pie cool on a rack, then refrigerate until chilled before serving.
The pie can be refrigerated overnight.