Preheat oven to 350 degrees F.

Prepare crust: In a medium bowl, stir together flour, sugar, and salt. Gentle combine with softened butter (I used my hands for this step). Press into the bottom of a 9x9 inch pan. Bake until crust is firm and golden brown, about 20-25 minutes. Set aside.

In another medium bowl, whisk together the sugar and flour for the filling. Whisk eggs in one egg at a time. Whisk in lemon juice and zest. Pour mixture over baked crust.

Bake for 30 minutes, bars will firm up while they cool. Let cool completely. Dust with powdered sugar and serve.