Key Lime Tart Recipe

Preheat oven to 350°F (175°C). Lightly butter a 9-inch tart pan with removable bottom.

Place graham crackers in a food processor and pulse until fine crumbs form. Alternatively, place in a zip-top bag and crush with a rolling pin.

Combine graham cracker crumbs, 2 tablespoons granulated sugar, and 1 teaspoon fine salt in a bowl. Melt 6 tablespoons unsalted butter and pour over crumbs. Stir until evenly moistened and mixture holds together when pressed.

Press the crumb mixture firmly and evenly into the bottom and up the sides of the prepared 9-inch tart pan, using the bottom of a measuring cup or a flat glass. Work quickly to get a compact crust about 1/4–1/3 inch thick.

Bake crust in the preheated oven for 8–10 minutes, until fragrant and set. Remove from oven and let cool slightly while preparing the filling. Reduce oven temperature to 325°F (160°C).

In a medium bowl, whisk together 14 oz sweetened condensed milk and 1 cup fresh key lime juice until smooth and slightly thickened.

Whisk in 5 egg yolks, one at a time, until fully incorporated. Stir in 2 tablespoons lime zest and a pinch of fine salt.

Pour the filling into the warm but not piping-hot baked crust, smoothing the top with a spatula.

Bake at 325°F (160°C) for 12–15 minutes, until the filling is set at the edges but still has a slight jiggle in the center (it will finish setting as it cools). Avoid overbaking to keep the filling creamy.

Remove tart from oven and let cool on a wire rack for 30–45 minutes, then refrigerate for at least 2 hours (preferably 3–4 hours) until fully chilled and firm.

Ensure the tart is chilled before adding meringue. Preheat a small saucepan of water to a gentle simmer to make a double-boiler setup.

In a heatproof bowl (bowl should not touch simmering water), combine 5 large egg whites, 3 tablespoons granulated sugar, and 1 teaspoon cornstarch. Whisk gently to combine.

Place the bowl over the simmering water and whisk constantly until the sugar is dissolved and the mixture reaches about 160°F (70°C) or feels warm and smooth when rubbed between fingers (no graininess), about 2–3 minutes.

Remove the bowl from heat. Add 1 teaspoon cream of tartar and 1/2 teaspoon vanilla extract. Using an electric mixer, beat the warmed egg whites on medium-high speed until stiff, glossy peaks form, about 4–6 minutes.

Immediately spoon or pipe the meringue over the chilled tart, creating peaks and swirls with the back of a spoon or an offset spatula so there are high points to torch.

Use a kitchen torch to gently brown the meringue until golden on the peaks (keep torch moving to avoid burning). If you don’t have a torch, place the tart under a hot broiler set to high for 30–60 seconds, watching carefully to avoid over-browning.

After toasting, let the tart sit at room temperature for 10–15 minutes, then transfer to the refrigerator for 15–30 minutes to set the meringue layer.

Garnish with 1 teaspoon extra lime zest and an optional light dusting of powdered sugar just before serving.

Carefully remove the tart from the tart pan and slice with a sharp knife dipped in hot water and wiped dry between cuts for clean slices.

Serve chilled or at cool room temperature. Store leftover tart covered in the refrigerator up to 3 days.