Preheat oven to 350°F and prepare an 8x8-inch baking dish with parchment paper. Set aside
Mix the crust ingredients together with a pastry cutter or a fork until the dough resembles a light crumble.
1½ cup all-purpose flour, ½ cup powdered sugar, 12 tablespoons unsalted butter, ⅛ teaspoon kosher salt
Press the crust into the prepared baking dish in an even layer
Bake for 10-15 minutes, or until it turns a light golden color.
Remove and let cool completely.
In a separate bowl, whisk the filling ingredients together until smooth.
1¾ cups granulated sugar, 1 teaspoon pure vanilla extract, ¾ cup fresh lemon juice, 2 teaspoons lemon zest, 3 large eggs, ⅓ cup all-purpose flour
Pour it onto the crust and bake for 25 more minutes.
Remove and let cool completely before refrigerating for 2 hours.
Before slicing, sift the powdered sugar over the uncut bars.
¼ cup powdered sugar
Cut into 9 equal pieces and serve.