Preheat Oven: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan and line it with parchment paper, leaving some overhang for easy removal.

Prepare the Crust and Topping:

In a large mixing bowl, combine the softened butter, flour, granulated sugar, and salt. Mix until the mixture resembles coarse crumbs.

Press about two-thirds of the mixture evenly into the prepared baking pan to form the crust. Reserve the remaining one-third for the crumb topping.

Bake the crust in the preheated oven for 15-20 minutes, or until it is lightly golden. Remove from the oven and let it cool slightly.

Make the Lemon Filling:

In a medium mixing bowl, whisk together the eggs, granulated sugar, flour, lemon juice, and lemon zest until smooth and well combined.

Pour the lemon filling over the partially baked crust, spreading it evenly.

Add the Crumb Topping:

Sprinkle the reserved crumb mixture evenly over the lemon filling.

Bake:

Return the pan to the oven and bake for an additional 20-25 minutes, or until the filling is set and the top is lightly golden.

Cool and Cut:

Allow the bars to cool completely in the pan. Once cooled, use the parchment paper overhang to lift the bars out of the pan. Cut into squares or bars.

Serve:

Dust with powdered sugar before serving, if desired.

Enjoy your tangy and sweet Lemon Crumb Bars!