01 - Preheat oven to 350°F. Line a 9x13-inch baking pan with parchment paper, allowing an overhang for easy removal.
02 - In a medium bowl, cream together butter and sugar until light and fluffy. Blend in flour and salt until the mixture resembles coarse crumbs and holds together when pressed.
03 - Press the dough firmly and evenly into the bottom of the prepared pan. Bake for 18 to 20 minutes until the edges are lightly golden.
04 - While the crust bakes, whisk together eggs and sugar in a separate bowl until well blended. Sift in the flour and whisk until smooth. Stir in the fresh lemon juice and zest.
05 - Reduce oven temperature to 325°F. Pour the lemon filling over the hot crust. Return to the oven and bake for 18 to 20 minutes, or until the center is set and no longer jiggles when shaken.
06 - Cool completely in the pan on a wire rack. Use the parchment overhang to lift the bars out. Cut into squares and dust generously with powdered sugar before serving.