Preheat oven: Set to 175°C and line a 20x30 cm baking pan with parchment paper.
Make crust: In a bowl, mix flour, powdered sugar, and salt. Cut in cold butter until crumbly. Press into pan and bake 20 minutes until lightly golden.
Prepare filling: Whisk together eggs, sugar, flour, lemon juice, and zest until smooth.
Bake again: Pour lemon mixture over hot crust. Bake 15–20 minutes until center is set.
Cool & dust: Let cool completely, refrigerate 1 hour, then dust with powdered sugar before slicing.