cups graham cracker crumbs from 9 (2¼-inch by 4¾-inch) crackers
tbsp unsalted butter, melted
(14-oz) can sweetened condensed milk
large egg yolks
cup plus 2 tbsp fresh or bottled Key Lime juice (if using bottled, preferably Manhattan Brand)
cup chilled heavy cream
Make Crust: Preheat oven to 350 degrees 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. Bake crust in middle of oven 10 minutes and cool in pie plate on a rack. Leave oven on. Make Filling and Bake Pie: 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 in middle of oven 15 minutes. Cool pie completely on rack (filling will set as it cools), then chill, covered, at least 8 hours. Make Topping: Just before serving, beat cream in a bowl with an electric mixer until it just holds stiff peaks. Serve pie topped with cream. NOTE: Pie (without topping) can be chilled up to 1 day.