Serendipity’s Lemon Ice Box Pie
1 1/2 cups graham cracker crumbs
2 tablespoons ground cinnamon
1/2 cup unsalted butter, melted and cooled
2 (14 ounce) cans sweetened condensed milk
4 large egg yolks
1/2 cup lemon juice (4-6 lemons)
1 lemon, zest of (optional)
In a medium bowl, combine graham cracker crumbs, cinnamon, and butter until fully incorporated. Scrape mixture into a 9" pie pan. Using your fingers or the back of a sppon, press mixture firmly onto the base and up the sides of the pan, forming a uniform crust about 1/4" thick. Refrigerate until ready to use.
In a medium nonstick saucepan, whisk together sweetened condensed milk, egg yolks, and lemon juice until smooth. Cook custard over medium heat until very hot to the touch, about 10 minutes, stirring occasionally with a wooden spoon. Do not allow to boil.
Strain custard through a sieve into prepared pie shell. (If using lemon zest, strain through sieve into another bowl. Fold in lemon zest and pour into pie shell.) Smooth the filling, forming a slight dome in the center. Refrigerate uncovered at least 1 hour, or until set. Cover with plastic wrap and chill completely, at least another hour.
Serve wedges cold with plenty of whipped cream. Store covered in refrigerator.