This version of key lime pie has a lime-scented graham cracker crust, a dense sweet/tart lime layer, topped with a tangy, creamy lime curd. Fresh key limes aren't always to easy to find so feel free to use the more available bottled key lime juice, or if you can't find either go ahead and use Persian limes.

Key Lime Pie

Crust:
1 1/2 cups graham cracker crumbs
1/2 cup unsalted butter, melted
2 tablespoons sugar
Freshly grated zest of 1/2 lime

Filling:
1 (14-ounce) can sweetened condensed milk
1/2 cup lime juice, strained
4 large egg yolks
Freshly grated zest of 1/2 lime

Topping:
1 cup sugar
2/3 cup lime juice
8 large egg yolks
1/4 to 1/2 teaspoon lime oil, optional

Whipped Cream:
1 1/2 cups heavy cream
5 tablespoons sugar

1. Preheat oven to 350°F (175°C). Spray a 9 1/2-inch deep-dish pie plate with nonstick cooking spray.
2. To make the crust, place the graham cracker crumbs, melted butter, sugar, and zest in a bowl. Stir to combine. Pour the mixture into the prepared pie plate, and press with your fingers to create an even layer on the bottom and up the sides. Blind bake the crust for 5 to 7 minutes, or just until it starts to brown. Place on a wire rack to cool slightly.
3. Meanwhile, prepare the filling. Whisk together the condensed milk, lime juice, egg yolks, and zest. Pour the mixture into the partially baked crust. Bake for 10 minutes. Then return the pie to a wire rack to begin cooling.
4. While the filling is baking, prepare the topping. Place the sugar, lime juice, and egg yolks in the top of a double boiler. Cook over simmering water until the mixture is thick enough to coat the back of a spoon, about 15 minutes. When you draw a spoon across the bottom of the pan, it should leave a small path. Stir in the lime oil, if using, off the heat.
5. Gently pour the curd topping over the pie, completely covering the filling. Let the pie cool to room temperature on the wire rack. Then refrigerate it for at least 4 hours, or overnight.
6. Right before serving, prepare the whipped cream. Whip the heavy cream and sugar together until medium-firm peaks form. The cream should be whipped beyond the soft-peak stage, but not too stiff. Spread the whipped cream over the pie, all the way up the edges. Make peaks by repeatedly sweeping up the cream with the back of a spoon, up and out. Serve immediately.

Serves 8, making one 9 1/2-inch pie.