Classic Key Lime Pie

This classic pie includes a flaky pastry crust, billowy whipped-cream topping, and of course a silky, aromatic sweet-tart custard filling. If you can’t find fresh Key limes, you can substitute common lime juice, which will be tart but without the floral notes found in Key limes. Bottled Key lime juice is an even better choice as long as it’s 100% juice. The pie needs to chill for at least 5 hours before serving.

For the crust

• 4-1/2 oz. (1 cup) unbleached all-purpose flour; more as needed
• 1-1/3 oz. (1/3 cup) cake flour
• 1 tsp. granulated sugar
• 1/4 tsp. table salt
• 4 oz. (1/2 cup) cold unsalted butter, cut into 8 pieces
• 1/4 cup ice-cold water
• 1 tsp. cider vinegar

For the filling and topping

• 4 large egg yolks
• 1 14-oz. can sweetened condensed milk
• 1/2 cup fresh Key lime juice (from 14 to 16 limes) or bottled Key lime juice (preferably Manhattan brand)
• 1-1/2 cups cold heavy cream
• 1 oz. (1/4 cup) confectioners’ sugar
• 3/4 tsp. pure vanilla extract

Make the crust

In a food processor, pulse the flours, sugar, and salt to combine. Add the butter and begin cutting it into smaller pieces with four 1-second pulses.

In a small bowl, combine the water and vinegar. While pulsing, gradually add the liquid in a thin stream through the feed tube until the dough forms several large clumps, 20 to 30 pulses. The butter should still be visible in small pieces.

Gather and press the dough into a 1-inch-thick disk. Wrap in plastic and refrigerate for at least 1 hour.

Dust a work surface and both sides of the dough lightly with flour. Flatten the dough slightly by tapping it all over with a rolling pin, then roll the dough out into a 12-inch circle. Try to make the circle as even as possible, but don’t be concerned about rough edges.

Roll the dough around the rolling pin and carefully unroll over a 9-inch glass or metal pie plate. Gently press it into the bottom and up the sides of the pan without stretching it. With scissors, trim the overhanging dough to 1/2 inch beyond the rim of the plate. Fold the overhang under and crimp decoratively. Wrap the crust in plastic and refrigerate for at least 1 hour.

Position a rack in the center of the oven and heat the oven to 400°F.

Line the crust with aluminum foil and fill with dried beans or pie weights. Put the crust on a rimmed baking sheet and bake until the edge is firm and pale golden, 20 to 25 minutes. Carefully remove the foil and beans. Prick the bottom of the crust all over with a fork. Continue baking until golden-brown, 8 to 12 minutes. (If the pastry puffs up, gently prick it with a toothpick.) Transfer to a wire rack and cool to room temperature.

Fill and bake the pie

Reduce the oven temperature to 350°F.

In a medium bowl, vigorously whisk the egg yolks by hand until slightly thickened, about 1 minute. Gently whisk in the sweetened condensed milk until combined, then whisk in the lime juice; the filling will thicken just a bit. Scrape the filling into the crust and spread it evenly.

Bake on a rimmed baking sheet for 20 minutes—the filling will be only partially set. Cool to room temperature on a rack, then refrigerate until the filling is completely set, at least 5 hours.

Top the pie

Chill a metal bowl and the beater(s) of an electric mixer. In the chilled bowl, combine the cream, confectioners’ sugar, and vanilla. Beat on medium-high speed to firm peaks. Spoon the cream over the filling, swirling it attractively. Slice and serve.