Key Lime Pie Recipe

Prepare oven and pan

Preheat the oven to 350°F (175°C). Lightly butter a 9-inch (23 cm) pie dish or use nonstick spray.

Combine graham cracker crumbs, granulated sugar, melted butter, and salt in a medium bowl. Mix with a fork or spatula until the mixture is evenly moistened and holds together when pressed.

Press the crumb mixture firmly and evenly into the bottom and up the sides of the prepared 9-inch pie dish, using the bottom of a measuring cup or a glass to compact the crust and create a neat edge.

Bake the crust on the middle rack for 8–10 minutes, until set and fragrant. Remove from oven and let cool slightly while preparing the filling. Reduce oven temperature to 325°F (160°C) if you will briefly bake the assembled pie; otherwise cool completely and chill.

In a medium bowl, whisk together the sweetened condensed milk and the key lime zest until combined and aromatic.

In a separate bowl, lightly whisk the egg yolks just to break them and make them smooth. Temper the yolks: whisk a few tablespoons of the condensed milk mixture into the yolks to slightly warm them, then whisk the yolk mixture back into the remaining condensed milk.

Stir in the fresh key lime juice and a pinch of salt. Mix until the filling is smooth and slightly thickened. The acid in the juice will help thicken the filling.

Pour the filling into the warm (not hot) prebaked crust and smooth the top with a spatula.

Bake the pie at 325°F (160°C) for 12–15 minutes, or until the center is just set — it should still have a slight jiggle but not be liquid. (If you prefer a fully chilled, no-bake style, omit this bake step and chill the pie for at least 4 hours or overnight; baking gives a silkier texture.)

Remove the pie from the oven and let cool on a wire rack to room temperature, about 1 hour. Then refrigerate for at least 3 hours (preferably overnight) to fully chill and set.

For the topping, chill a medium mixing bowl and beaters in the freezer for 5–10 minutes (optional but helps the cream whip faster).

Pour the heavy whipping cream into the chilled bowl. Add confectioners' sugar and vanilla. Beat on medium-high speed with a hand mixer or stand mixer until soft peaks form, about 2–3 minutes. Do not overbeat or it will turn grainy.

Spread or pipe the whipped cream over the chilled pie. Garnish with the reserved lime zest. Refrigerate until ready to serve.

Slice the pie with a sharp knife dipped in hot water and wiped dry between cuts for clean slices. Serve chilled. Keeps well covered in the refrigerator for up to 3 days.