Preheat the oven to 350°F. Line a 9-by-13-inch baking pan with foil, leaving a 2-inch overhang on two sides. Coat the foil with cooking spray. Mix 2 cups flour, the confectioners’ sugar and salt in a large bowl with a whisk. Work in the butter with your fingers until large clumps form.

Press the crust mixture into the pan in an even layer. Bake until lightly browned, 20 to 25 minutes. Remove the pan from the oven with mitts, then put the pan on a rack and let cool 5 minutes.

Meanwhile, combine the eggs, granulated sugar, lemon juice and remaining 1/3 cup flour in a large bowl and mix with a whisk until smooth. Pour the lemon mixture over the warm crust.

Bake until the lemon bars are set, 20 to 25 minutes. Remove the pan from the oven with oven mitts, then put the pan on the rack and let the bars cool completely.

Lift the bars out of the pan using the overhanging foil, then peel off the foil. Dust the tops of the bars with confectioners’ sugar using a sifter. Cut into squares.