1. Preheat the Oven:
Set your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper and lightly grease it.

2. Make the Crust:
In a large bowl, beat the butter and sugar until creamy. Add the flour and salt, and mix until a crumbly dough forms. Press the dough evenly into the bottom of the pan. Bake for 18–20 minutes, or until lightly golden. Remove from the oven and set aside.

3. Make the Lemon Filling:
In a mixing bowl, whisk the sugar and flour together. Add the eggs, lemon juice, and zest. Whisk until smooth and fully combined.

4. Pour and Bake:
Pour the lemon filling over the warm crust and return to the oven. Bake for 20–25 minutes, or until the center is just set and no longer jiggly.

5. Cool and Dust:
Let the bars cool completely in the pan. Then refrigerate for at least 2 hours before slicing. Dust with powdered sugar just before serving.

6. Slice and Serve:
Use a sharp knife to cut clean bars. Wipe the knife between cuts for professional-looking slices.