Another fabulous recipe from Cook’s Illustrated Magazine.These really are perfect!
The lemon filling must be added to a warm crust. The 30-minute chilling and 20-minute baking of the crust should allow plenty of time to prepare the filling. If not, make the filling first and stir to blend just before pouring it into the crust. Any leftover bars can be sealed in plastic wrap and refrigerated for up to two days. Makes about 2 dozen 1½- to 2-inch squares.
1 ¾ cups all-purpose flour
2/3 cup confectioners’ sugar, plus extra to decorate finished bars
¼ cup cornstarch
¾ teaspoon salt
12 tablespoons unsalted butter (1 ½ sticks), at very cool room temperature,
cut into 1-inch pieces, plus extra for greasing pan
4 large eggs, beaten lightly
1 1/3 cups granulated sugar
3 tablespoons all-purpose flour
2 teaspoons finely grated zest from two large lemons
2/3 cup juice from 3 to 4 large lemons, strained
1/3 cup whole milk
1/8 teaspoon salt
For the crust: Adjust oven rack to middle position and heat oven to 350°. Lightly butter [or spray with cooking spray] a 13-by-9-inch baking dish and line with one sheet parchment or wax paper. Dot paper with butter [or spray with cooking spray], then lay second sheet crosswise over it.
Pulse flour, confectioners’ sugar, cornstarch, and salt in food processor workbowl fitted with steel blade. Add butter and process to blend, 8 to 10 seconds, then pulse until mixture is pale yellow and resembles coarse meal, about three 1-second bursts. (To do this by hand, mix flour, confectioners’ sugar, cornstarch, and salt in medium bowl. Freeze butter and grate it on large holes of box grater into flour mixture. Toss butter pieces to coat. Rub pieces between your fingers for a minute, until flour turns pale yellow and coarse.) Sprinkle mixture into lined pan and, press firmly with fingers into even, ¼-inch layer over entire pan bottom and about ½ inch up sides. Refrigerate for 30 minutes, then bake until golden brown, about 20 minutes.
For the filling: Meanwhile, whisk eggs, sugar, and flour in medium bowl, then
stir in lemon juice and zest, milk, and salt to blend well.
To finish the bars: Reduce oven temperature to 325°. Stir filling mixture to reblend; pour into warm crust. Bake until filling feels firm when touched lightly, about 20 minutes. Transfer pan to wire rack; cool to near room temperature, at least 30 minutes. Transfer to cutting board by pulling up the wax paper lining, fold wax paper down, and cut into serving-size bars, wiping knife or pizza cutter clean between cuts, as necessary. Sieve confectioners’ sugar over bars, if desired.