- 1.25 cups graham cracker crumbs
- 3 tbsp granulated sugar
- pinch of salt
- 6 tbsp (3/4 stick) unsalted butter, melted
- 1 can (14.5 oz) sweetened condensed milk
- 4 large egg yolks
- 1/2 cup (about 20 limes) key lime juice
- 1 tbsp lime zest
- (optional) green food coloring
- 3/4 cup cold heavy whipping cream
- Preheat oven to 350 F and position an oven rack in the middle. Grease the pie plate.
- To make the crust: In a food processor fitted with a metal blade, add the graham crackers and process until fine, about 1 minute. Add the sugar and salt and process until combined. Drizzle in the melted butter and process until the crumbs are moist, about 1 minute.
- Press the graham cracker crust evenly into the bottom and up the sides of the pie plate. Transfer to the refrigerator and chill until firm, about 15 minutes. Bake until the crust is set and lightly browned, about 12 minutes. Transfer pie plate to a wire rack and leave to cool completely.
- To prepare the filling: In a medium bowl, combine the condensed milk, yolks, lime juice, and zest. If desired, add a touch of green food coloring. Pour the filling into the crust. Return the pie to the oven and bake until center is just set, about 15-17 minutes. Transfer pie to wire rack and cool to room temperature. Cover and refrigerate until serving time.
- Pour cream into a medium bowl and whip the cream until soft peaks form.
- To serve: Cut the pie into wedges and garnish with a dollop of cream. Serve immediately.