CRUST:

11 graham crackers, crushed (1 1/2 c. crumbs)
2 tbsp. sugar
1/2 stick (2 oz.) unsalted butter, melted

Combine. Press mixture evenly into a 9-inch pie pan. Refrigerate 1 hour.

FILLING:

4 egg yolks
1 (14 oz.) can sweetened condensed milk
3 oz. key lime juice
Grated zest of 1 green lime

Combine yolks and milk. Beat well. Add lime juice gradually, while stirring. Add lime zest. Stir until smooth and creamy. Pour into crust and bake in a preheated 350 degree oven for 10 minutes. Serve chilled with whipped cream.