01 - Preheat the 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 butter and sugar until light and fluffy. Add the flour and salt, and mix until just combined.
03 - Press the crust mixture evenly into the prepared pan. Bake for 18-20 minutes, or until lightly golden.
04 - Whisk together the sugar and flour in a large bowl. Add the eggs, lemon juice, and lemon zest; whisk until smooth.
05 - Pour the lemon filling over the hot crust as soon as it comes out of the oven.
06 - Return the pan to the oven and bake for another 15-18 minutes, or until the filling is set and no longer jiggly in the center.
07 - Let the bars cool completely in the pan. Once cool, lift out using the parchment overhang and cut into squares.
08 - Dust generously with powdered sugar before serving.