Preheat the oven to 350°F (175°C). In a blender or mixing bowl, combine all-purpose flour, corn flour, salt, powdered sugar, and cubed butter. Blend or knead with your hands until the mixture forms fine crumbs.
Line a 9×13-inch baking dish with foil and evenly press the crumb mixture into the pan, forming a slight border (about ½ inch). Bake for 20 minutes until lightly golden.
Filling
Zest two lemons and squeeze out the juice. In a bowl, whisk together eggs, lemon zest, lemon juice, sugar, and all-purpose flour until smooth and lump-free.
Pour the lemon filling over the baked crust and return to the oven. Bake for 20 minutes for a softer texture or 30 minutes for a firmer consistency.
Remove from the oven and let the lemon bars cool for about 2 hours. This allows them to set properly for easier slicing.
Once fully cooled, dust with powdered sugar and cut into squares or rectangles.