01 - Preheat oven to 350°F. Line a 9x13-inch baking pan with parchment paper, leaving an overhang for easy removal.
02 - In a medium bowl, cream butter and sugar until light and fluffy. Add flour and salt; mix until just combined. Press evenly into the prepared pan.
03 - Bake the crust for 18 to 20 minutes until edges are lightly golden.
04 - Whisk sugar and flour in a large bowl. Add eggs, lemon juice, and lemon zest; whisk until smooth.
05 - Pour lemon filling over hot crust. Return to oven and bake 15 to 18 minutes until filling is set and slightly jiggles.
06 - Remove from oven and cool completely in pan on wire rack. Refrigerate at least 2 hours for clean slicing.
07 - Lift bars out using parchment overhang. Dust with powdered sugar and cut into squares.