1 1/4 cups graham cracker crumbs from 9 (2 1/4-inch by 4 3/4-inch) crackers
2 tablespoons sugar
5 tablespoons unsalted butter, melted
1 (14-ounce) can sweetened condensed milk
4 large egg yolks
1/2 cup plus 2 tablespoons fresh or bottled Key lime juice
1 T. grated lime zest
3/4 cup chilled heavy cream
Preheat oven to 350°F.
Stir together graham cracker crumbs, sugar, and butter in a bowl with a fork until combined well, then press mixture evenly onto bottom and up side of a 9-inch pie plate.
Whisk together condensed milk and yolks in a bowl until combined well. Add juice and whisk until combined well (mixture will thicken slightly).
Pour filling into crust and bake for 15 minutes. Cool pie completely on rack (filling will set as it cools), then chill, covered, at least 8 hours.
Just before serving, beat cream in a bowl with an electric mixer until it just holds stiff peaks. Serve pie topped with cream.
**As a fun variation, press graham cracker crumbs in muffin tin to make individual mini key lime pies!! We made those for Erin's baby shower and they were a hit!