01 - Preheat the oven to 350°F. Line a 9x13-inch baking pan with parchment paper, leaving overhang for easy removal.
02 - In a medium bowl, beat softened butter and 1/2 cup granulated sugar until light and fluffy.
03 - Add 2 cups all-purpose flour and 1/4 teaspoon salt; mix just until combined. Press the dough evenly into the prepared pan.
04 - Bake for 18–20 minutes, or until the edges are lightly golden. Remove from oven without turning it off.
05 - In a large bowl, whisk together 1 1/2 cups sugar and 1/4 cup flour. Add eggs, lemon juice, and lemon zest; whisk until fully blended and smooth.
06 - Pour the lemon mixture over the hot crust. Return pan to oven and bake for 15–18 minutes, until the center is just set and does not jiggle.
07 - Let cool completely in the pan on a wire rack for about 1 hour. Chill in the refrigerator for 30 to 60 minutes for best results.
08 - Use parchment paper overhang to lift bars from the pan. Dust generously with powdered sugar and cut into 16 squares.