• Prepare a 9 by 9 inch pan with parchment paper, and preheat an oven to 180c (350f).
• Make the crust: pulse graham crackers in a food processor until fine crumbs form. If you don’t have a food processor on hand, place the crackers in a Ziplock bag and smash the crackers with a cup until fine crumbs form.
• Into a small to medium mixing bowl, add the graham crackers crumbs, sugar, and melted butter. Mix with a spoon until the crumbs are coated with butter.
• Transfer the crumbs into a prepared 9 by 9 inch pan, pressing evenly and firmly into the pan.
• Bake the crust in a 180c (350f) preheated oven for 8 minutes. Keep an eye on the crust and make sure it doesn’t burn. Take the crust out of the oven and let it cool to room temperature while you make the filling.

Make the filling

• In a large mixing bowl, add the flour, sugar, and kosher salt, and mix well with a whisk.
• Add the lemon zest and mix well to release the lemon zest's natural oils and flavors.
• Add the lemon juice, eggs, and mix with a whisk until well combined.
• Pour the lemon mixture over the baked graham cracker crust. Bake in a 180c (350f) preheated oven for 20 minutes or until the edges of the bars are set, and the middle is a bit jiggly.
• Let them cool to room temperature, then transfer them to the fridge to cool and set for at least 4 hours.
• Slice the bars into 16 slices or 9 large slices with a sharp knife. Top them with plenty of powdered sugar and serve!