1 stick melted butter (1/4 pound)
1/3 cup brown sugar
10 egg yolks
2 cups sweetened condensed milk
1 1/2 cups key lime juice or about 2 pounds key limes, juiced
1 cup egg whites
2 cups granulated sugar
Preheat oven to 300°.
To make the crust: Combine Graham cracker crumbs, melted butter, and brown sugar in a stainless steel bowl, mix well. Press into a 10-inch glass pie pan to about 1/4 inch thickness.
To make the filling: Mix egg yolks with sweetened condensed milk. Add lime juice and stir until completely combined. Pour into prepared pie shell and bake for approximately 1 hour to 1 hour, 15 minutes. Custard should be slightly firm to the touch. Cool, cover with plastic wrap and chill in refrigerator.
To make the meringue: Place egg whites and sugar into mixing bowl of an electric mixer. Place bowl over a saucepan of boiling water, as you would a double boiler (bowl should not be in the water). You can also pour egg whites and sugar into the top of a double boiler, then later put in mixing bowl to whip (or use hand-held mixer). Heat whites, stirring with a whisk until they are hot to the touch, about 120°.
Preheat oven to 500°. Remove bowl from saucepan with water. Place whip attachment on electric mixer and whip on high speed until whites form stiff peaks and are cool.
Daub any moisture on top of chilled pie with paper towel. Top with whipped meringue, being sure to cover completely, and bake in hot oven until meringue is very lightly browned (2 to 3 minutes — watch carefully).
Cooks Note: if you can’t find the key limes you can use Nellie and Joe’s Key Lime Juice, which is available at the grocery stores. Key limes are more delicate and flavorful than the common Persian lime. Do not substitute. Note that the recipe uses a homemade graham cracker crust. Plan ahead because the Key lime filling takes more than an hour to bake and then needs to be chilled.