Preheat the oven to 350°F and grease a 9"x13" glass pan.
For the crust, combine the butter, sugar, salt, and flour in a medium mixing bowl. Mix until fully combined. The consistency should be crumbly.
Press the dough into the prepared pan and bake for 15 minutes. Let the crust cool for 5 minutes.
Meanwhile, start the lemon filling by combining the eggs, flour, sugar, and lemon juice in a medium mixing bowl. Mix until fully incorporated.
Pour the lemon filling mixture over the crust and bake for 25 minutes at 350°F. Let the lemon bars cool for at least an hour so they can fully set up. Dust the top with powdered sugar and serve.
Notes
You can speed up the cooling process by putting your lemon bars in the fridge to help them set up quicker!