Step 1

Preheat the oven to 325°. In a food processor, pulse the graham crackers with the sugar and salt until finely ground but not powdery. Add the butter and pulse until the crumbs are evenly moistened; transfer to a 9-inch springform pan and press into the bottom and two-thirds up the side. Set the pan on a rimmed baking sheet.

Step 2

In a medium bowl, whisk the condensed milk with the lemon juice. In another bowl, using a handheld mixer, beat the lemon zest with the egg yolks until pale. Beat in the condensed milk mixture until smooth. Pour the filling into the crust.

Step 3

Bake the pie for 25 minutes, until the center jiggles slightly and the edges are set. Transfer the pan to a rack; let cool for 1 hour. Loosely cover the pan with plastic wrap and freeze the pie for at least 6 hours.

Step 4

Wrap a warm, damp kitchen towel around the side of the springform pan to release the pie; remove the ring. Using a hot knife, slice the pie, transfer to plates and serve.