Step 1

Preheat oven to 350°F.

Step 2

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 (4-cup) glass pie plate.

Step 3

Bake crust in middle of oven 10 minutes and cool in pie plate on a rack. Leave oven on.

Step 4

Whisk together condensed milk and yolks in a bowl until combined well. Add juice and whisk until combined well (mixture will thicken slightly).

Step 5

Pour filling into crust and bake in middle of oven 15 minutes. Cool pie completely on rack (filling will set as it cools), then chill, covered, at least 8 hours.

Step 6

Just before serving, beat cream in a bowl with an electric mixer until it just holds stiff peaks. Serve pie topped with cream.

Step 7

*Available at Manhattan Key Lime (212-696-5378).