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 together the softened butter and 1/2 cup sugar until light and fluffy. Add flour and salt; mix until just combined. Press evenly into the bottom of the prepared pan.
03 - Bake the crust for 18 to 20 minutes until lightly golden.
04 - While the crust bakes, whisk together 1 1/2 cups sugar, 1/4 cup flour, eggs, lemon juice, and lemon zest in a large bowl until smooth and fully combined.
05 - Pour the lemon filling carefully over the hot crust immediately after removing it from the oven.
06 - Return to the oven and bake for 15 to 18 minutes, or until the filling is just set and no longer jiggly in the center.
07 - Remove from oven and cool completely in the pan on a wire rack. Once cooled, lift out using the parchment overhang and cut into bars.
08 - Dust bars generously with powdered sugar before serving.