Key Lime Tarts Recipe

Preheat and prepare tins

Preheat the oven to 350°F (175°C). Lightly spray or butter twelve 3-inch tartlet pans or a 9-inch tart pan with removable bottom.

Combine the graham cracker crumbs and granulated sugar in a medium bowl. Add the melted butter and salt; stir until mixture resembles wet sand and holds together when pressed.

Divide the crumb mixture evenly among the tart pans (about 2 tablespoons per 3-inch tart) and press firmly into the bottom and up the sides with the back of a spoon or the bottom of a measuring cup to form an even shell about 1/8–1/4 inch thick.

Bake shells for 8–10 minutes, until set and fragrant. Remove from oven and let cool slightly while you make the filling. Leave oven on.

In a medium bowl, whisk together the egg yolks until smooth and slightly pale (about 30 seconds).

Add the sweetened condensed milk to the yolks and whisk until fully combined and smooth.

Whisk in the key lime juice, lime zest, sour cream, vanilla extract, and a pinch of salt until the mixture is glossy and homogeneous. Do not overmix; you want a smooth filling without incorporating too much air.

Pour or spoon the filling evenly into the baked crusts, filling each tart almost to the top (leave a little room for slight expansion). For a 9-inch tart, pour all filling into the prepared tart shell.

Reduce oven temperature to 325°F (160°C). Bake the tartlets for 10–12 minutes, or the 9-inch tart for 15–18 minutes, until the edges are set but the center still slightly jiggles — the residual heat will finish cooking.

Remove tarts from oven and let cool to room temperature on a wire rack for about 30–45 minutes, then chill in the refrigerator for at least 2 hours (preferably 4) until fully set.

Place a medium mixing bowl and beaters in the freezer for 10 minutes beforehand if possible to help the cream whip faster.

Pour the cold heavy cream into the chilled bowl, add the powdered sugar and vanilla extract. Beat with an electric mixer on medium-high until soft peaks form (about 1–2 minutes). Do not overbeat — stop when peaks hold but are still silky.

Pipe or dollop a small amount of whipped cream onto each chilled tart before serving.

Finish each tart with a thin slice or wedge of lime and a sprinkle of extra lime zest. Serve chilled. Leftover tartlets will keep covered in the refrigerator for up to 3 days.