Key Lime Pie Recipe

Brown the butter

Melt the 6 tbsp salted butter in a light-colored saucepan over medium heat. Swirl frequently; after foaming subsides watch closely as the milk solids brown and the butter smells nutty, about 5–6 minutes. Remove from heat immediately and transfer to a small bowl to stop cooking.

Combine crumbs

In a mixing bowl, combine 1 1/2 cups graham cracker crumbs, 3 tbsp granulated sugar, 1/4 cup finely chopped toasted pecans (if using), and 1/4 tsp fine salt. Pour the warm brown butter over the crumbs and stir with a fork until evenly moistened and the mixture holds together when pressed. Reserve 1/4 cup of this crumble for finishing and set aside.

Press into pan

Press the remaining crumble firmly into the bottom and slightly up the sides of a 9-inch pie dish (or 9-inch tart pan) to form an even crust. Use the bottom of a measuring cup to compact. Chill in the refrigerator for 15 minutes to set while you prepare the filling.

Bake (optional for crisper crust)

Optional: Preheat the oven to 350°F (175°C) and bake the crust for 8–10 minutes until fragrant and set. Let cool slightly before filling. If you prefer a chewier crust, skip baking and proceed chilled.

Preheat oven

If you baked the crust, keep the oven at 350°F (175°C). If the crust was not baked, preheat oven to 325°F (160°C) for gentler baking of the custard.

Whisk filling

In a medium bowl, whisk together 14 oz sweetened condensed milk and 4 large egg yolks until smooth and slightly thickened. Whisk in 3/4 cup fresh key lime juice, 1 tbsp key lime zest, 1/2 cup heavy cream, and 1/2 tsp vanilla extract until fully incorporated and glossy. Strain the mixture through a fine mesh sieve into a pourable container to remove any coagulated egg bits and excess zest for a silky texture.

Bake filling

Pour the strained filling into the chilled/baked crust. Place the pie on a sheet pan and bake until the center is just set but still slightly jiggly (center temperature ~150°F / 65°C), about 15–22 minutes depending on oven and pan. If using the higher temperature, check at 15 minutes. Avoid overbaking to keep the filling creamy.

Cool and chill

Remove pie from oven and let cool to room temperature on a wire rack for 30–45 minutes, then refrigerate uncovered for at least 4 hours (preferably overnight) to fully set and develop flavor.

Prepare limes

Thinly slice 3 key limes into 1/8-inch rounds; remove any seeds. Blanch the slices in boiling water for 30 seconds then drain to reduce bitterness.

Candy the slices

In a small nonreactive skillet, combine 1/2 cup granulated sugar and 1/2 cup water and bring to a simmer. Add the lime slices in a single layer and simmer gently for 12–15 minutes until the rinds become translucent and the syrup thickens slightly. Turn slices occasionally to candied evenly.

Dry and store

Using a slotted spatula, transfer candied slices to a wire rack set over parchment to cool and dry. Reserve 6 attractive slices for garnish. Any remaining syrup can be reduced briefly to a glaze and brushed lightly on finished slices.

Whip cream

Chill a mixing bowl and whisk or paddle for 5 minutes in the freezer. Pour 1 cup cold heavy cream into the bowl. Add 2 tbsp powdered sugar and 1/2 tsp vanilla bean paste or extract. Whip on medium-high speed until soft peaks form — do not overwhip. Transfer chantilly to a piping bag fitted with a large round or star tip if desired.

Assemble pie

Remove the chilled key lime pie from the refrigerator. Pipe or spoon dollops of vanilla chantilly around the edge or in the center as desired.

Garnish

Arrange 4–6 candied lime slices atop the chantilly. Sprinkle the reserved 1/4 cup brown butter crumble around the edges and over the chantilly for crunch. Optionally brush candied lime slices with a little reduced syrup for shine and add micro mint leaves or a few curls of fresh lime zest for color.

Serve

Slice with a hot, dry knife for clean cuts. Serve chilled. Leftover pie can be stored covered in the refrigerator for up to 3 days; chantilly is best used within 24 hours.