How to Make It
Heat oven to 350° F.
In a food processor, combine 13/4 cups of the flour, the confectioners’ sugar, and 1/2 teaspoon of the salt. Pulse to blend. Add the butter and pulse until the mixture is crumbly.
Knead the dough in the bowl until it comes together. Press the dough evenly into a 9-by-13-inch baking dish, pushing the dough up about 1/2 inch around the sides. Refrigerate for 15 minutes. Bake until golden brown, about 30 minutes.
Meanwhile, in a large bowl, whisk together the eggs, granulated sugar, lemon zest, and the remaining flour and salt. Add the lemon juice and whisk until smooth.
Pour the mixture over the hot crust.
Reduce oven temperature to 300° F. Bake until the filling is set, about 15 minutes.
Transfer dish to a wire rack and let cool.
Dust with additional confectioners’ sugar.
Cut into 24 2-inch squares.