heat oven to 350 F and line a 9x13 inch pan with parchment leaving overhang
mix flour sugar and salt then cut in butter until crumbly and press firmly into an even layer
bake crust until set and lightly golden at the edges about 18 to 22 minutes.
Filling and Bake
whisk eggs and sugar until smooth then whisk in flour baking powder if using lemon zest lemon juice and salt until fully combined
pour filling over hot crust and bake until the center is just set and no longer wet looking about 22 to 28 minutes.
Cool and Serve
cool completely in the pan then chill 1 to 2 hours for clean slices
lift out using parchment and cut into bars
dust with powdered sugar just before serving.
Notes
1. Use fresh lemon juice for best flavor; For a firmer slice chill overnight; Reduce sugar to 1 3 4 cups for a more tart bar; No web browsing used recipe reflects a normalized classic lemon bar method