2 1/2 cups granulated sugar
2 tablespoons grated lemon zest (4-6 lemons)
1 cup freshly squeezed lemon juice
1 cup flour
Confectioners’ sugar, for dusting.
Pre-heat oven to 350°F and liberally butter a 9×13 by 2 inch baking sheet.
For the crust, cream the butter and sugar until light in a bowl of an electric mixer fitted with a paddle attachment. Combine the flour and salt and, with the mixer on low, add to the butter until just mixed. Gather mixture and form a ball. Flatten dough and press into buttered pan with floured hands, building up a 1/2 edge on all sides. Chill.
Bake the crust for 15-20 minutes, until very lightly browned. Let cool on wire rack. Leave the oven on.
For the lemon layer, whisk together the eggs, sugar, lemon zest, lemon juice, and flour. Pour over the crust and bake for 30-35 minutes, or about five minutes beyond the point where the filling is set. Let cool to room temperature.