• Preheat the oven to 350°F and line a 9 by 13 by 2-inch baking sheet with parchment. Lightly butter the parchment.

For the crust:

• Cream the butter, sugar and salt in the bowl of an electric mixer fitted with the paddle attachment. It should look a few shades lighter than when you began. With the mixer on low, add the flour until just mixed.
• Sprinkle tablespoon-sized chunks of dough all over the bottom on the pan and then press down to flatten and even it into the bottom, building up a 1/2-inch edge on all sides. Chill for at least 20 minutes. 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:

• In a food processor, combine all of the lemon peel and one cup of sugar. Process until completely combined, scraping down the bowl and pulsing a few more times until you can’t see anymore bits of peel. (if you don’t want to use a food processor, you could zest the lemons with a microplane and just add it to the sugar. It won’t be quite as lemony but will still be good).
• In a large bowl, whisk together the processed lemon zest/sugar, the remaining 1- 3/4 cup sugar, eggs, lemon juice, and flour. Pour over the crust and bake for 30 to 35 minutes until filling is just set. Let cool to room temperature.
• Cut into 1″ squares (or whatever size bars you like) and dust the lemon bars generously with confectioners’ sugar. If the sugar melts on top, just re-dust it and it will stay.