Lemon Squares

Directions

1. 1
   Preheat the oven to 325 degrees F and adjust rack to center.
2. 2
   Put the butter, flour, confectioners sugar, and salt in a food processor, and pulse in short intervals until the mixture is crumbly and resembles small peas.
3. 3
   Add the cold egg yolk and water to the mixture, and pulse until just mixed.
4. 4
   Place the dough on a floured surface, knead just a few times, and form into a disk.
5. 5
   Wrap in plastic, and keep in the refrigerator until cold, about 30 minutes.
6. 6
   When the dough is cold, roll it out on the floured work surface, and cover the bottom of a 9-by-13-inch pan with it.
7. 7
   Bake for 20 minutes, or until lightly golden.
8. 8
   Remove, and let cool slightly.
9. 9
   Whisk together the eggs, sugar, flour, baking powder, lemon juice, and zest in a bowl.
10. 10
    Pour the filling over the hot crust.
11. 11
    Bake for 30 minutes, until the lemon center sets.
12. 12
    Remove from the oven, cool completely, dust with confectioners sugar, and cut into squares.