01 - Preheat oven to 350°F. Line a 9x13 inch baking pan with parchment paper, allowing overhang on sides for easy removal.
02 - Cream together softened butter and 1/2 cup sugar in a large bowl until light and fluffy. Blend in 2 cups flour and 1/4 tsp salt, mixing just until dough forms.
03 - Press dough evenly into prepared pan bottom. Bake for 18-20 minutes until edges turn lightly golden.
04 - While crust bakes, whisk together 1 and 1/2 cups sugar and 1/4 cup flour in medium bowl. Add eggs, lemon juice, and lemon zest, whisking until completely smooth.
05 - Pour lemon mixture directly over hot crust immediately after removing from oven.
06 - Return to oven and bake 18-20 minutes longer until filling is just set in center—slight jiggle is okay.
07 - Let cool completely in pan. Lift out using parchment paper overhang and cut into 16 bars.
08 - Dust generously with powdered sugar immediately before serving.