Crust
14 whole graham crackers
1/4 cup sugar
1/4 teaspoon salt
6 tablespoons unsalted butter, melted but not cooled completely
Filling
2 14-oz cans sweetened condensed milk
1 1/4 cups lemon juice
zest of 2 lemons
8 large egg yolks
Preheat oven to 325 F.
To Make the Crust: Place the graham crackers, sugar and salt in the bowl of a food processor. Pulse until the graham crackers are fine, but not powdery, about 8 times. Pour in the butter and pulse until the mixture is no longer crumbly & holds its shape when you squeeze it, about 12 quick pulses. Transfer the mixture to a 9-inch springform pan and use your fingers (or the bottom of a measuring cup) to press the crust into the bottom and two-thirds of the way up the sides of the pan. Place on a rimmed baking sheet and set aside.
To Make the Filling: In a medium bowl, whisk the condensed milk with the lemon juice. In another medium bowl, whisk the lemon zest with the egg yolks until pale, about 30 to 60 seconds. Add the lemon juice/condensed milk mixture to the egg yolks and whisk to combine.
Pour the filling into the crust and bake until center jiggles slightly (like a soft-setting custard), about 25 minutes. Remove from the oven and move to a cooling rack to cool for at least an hour. Cover the springform pan with plastic wrap loosely (don't let the plastic wrap touch the top of the pie) and freeze for at least 6 hours or overnight.
To serve, wrap a warm towel around the edges of the springform pan to release the pie a bit. Open the collar and remove the pie. The pie will slice more easily if you use a knife dipped in a glass of hot water. The pie can be kept in the freezer for up to 1 week.