01 - Preheat oven to 350°F. Line a 9x13-inch baking pan with parchment paper, leaving an overhang on the sides for easy removal.
02 - In a medium bowl, cream together the softened butter and granulated sugar until light and fluffy. Add the flour and salt, mixing until combined and a crumbly dough forms.
03 - Press the dough evenly into the bottom of the prepared pan. Bake for 18-20 minutes or until the edges are lightly golden.
04 - While the crust bakes, whisk together the eggs and sugar in a separate bowl until well blended. Add the flour and whisk until smooth, then stir in the fresh lemon juice and lemon zest.
05 - Remove the crust from the oven and reduce the temperature to 325°F. Pour the lemon filling evenly over the hot crust. Return to the oven and bake for 18-20 minutes, or until the center is set and no longer jiggles when gently shaken.
06 - Cool completely in the pan on a wire rack. Use the parchment overhang to lift the bars out, then cut into 12 squares. Dust generously with powdered sugar before serving.