Preheat the oven to 350 degrees and line a 9x13 baking dish with parchment paper.
Using a large bowl and hand mixer, beat together the butter, sugar, eggs, lemon juice, and lemon zest.
Using a medium bowl, whisk together the flour and salt until combined.
Gradually beat in the dry ingredients.
Fold in the poppy seeds until combined.
Pour the batter into the baking dish and bake for 22-25 minutes or until the sides start to brown.
Allow cooling for 15 minutes.
Using a medium bowl, whisk together the powdered sugar, lemon juice, and lemon zest.
Pour the glaze over the bars and spread evenly.
Allow the glaze to harden before cutting into bars and enjoying.