• Preheat oven to 350° F. Lightly spray a 9″ x 13″ glass or ceramic baking pan with cooking spray. Or for clean cuts: line the pan with parchment paper, leaving an overhang on the long sides - and then use the sides to lift the finished bars out for easier cutting. Set aside.

For the Crust

• In a medium bowl, combine the butter, flour, powdered sugar, and salt. Mix with a large spoon or your fingers until well combined. Shape the dough into a ball and then pat it evenly into your prepared pan. Bake for 15 to 20 minutes, or until set and just beginning to turn color. Remove from oven.

For the Lemon Filling

• While the crust is baking, prepare the lemon filling. With an electric mixer on medium speed, beat together the eggs, sugar, lemon zest, lemon juice, and flour. Pour mixture over the warm baked crust and bake for an additional 30 to 35 minutes, or until the center is set and no longer jiggly. The top should be lightly golden brown.
• Remove the pan from the oven and let the bars cool completely at room temperature. I usually let them cool on the counter for about 2 hours and then put the pan in the refrigerator to chill for 1-2 hours.
• I recommend serving these chilled or even just slightly chilled. Once cool, dust with powdered sugar and cut into squares. Or cut into squares and then dust with powdered sugar. If lining the pan with parchment paper, cut around the edges of the pan to loosen, pull the bars out of the pan using the overhang on the sides, and place on a cutting board. Cut into squares with a long, non-serrated knife and wipe the knife clean between each cut. Finish with a dusting of powdered sugar