|For the crust:|
|1/2 lb unsalted butter, at room temperature|
|1/2 cup granulated sugar|
|2 cups flour|
|1/8 tsp kosher salt|
|For the full-size lemon layer:|
|6 extra-large eggs (room temperature)|
|2 1/2 cups sugar|
|2 tbsp lemon zest (grated 4 to 6 lemons)|
|1 cup lemon juice (freshly squeezed)|
|1 cup flour|
|1/2 cup confectioners sugar (for dusting)|
Preheat the oven to 350°F and grease a 9 by 13 by 2-inch baking sheet.
For the crust, cream the butter and sugar until light in the bowl of an electric mixer fitted with the paddle attachment. Combine the flour and salt and, with the mixer on low, add to the butter until just mixed. Dump the dough onto a well-floured board and gather into a ball. Flatten the dough with floured hands and press it into the greased baking sheet, building up a 1/2-inch edge on all sides. Chill.
Bake the crust for 15 to 20 minutes, until very lightly browned. Let cool on a 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 to 35 minutes (less if you are using the thinner topping), or about five minutes beyond the point where the filling is set. Let cool to room temperature.
Cut into rectangles and dust with confectioners’ sugar.