Preheat your oven to 350°F (175°C) and line a 8x8 inch baking dish with parchment paper.
In a mixing bowl, combine the graham cracker crumbs, brown sugar, and salt. Mix until well combined.
Pour in the melted butter and mix until crumbs are evenly coated. add to the prepared baking dish and press the mixture firmly into the bottom using a offset spatula or the bottom of a glass.
Bake the crust in the preheated oven for 10 minutes, then remove and set aside to cool slightly.
In a mixing bowl combine sugar, lemon zest an salt. Using your fingers, rub the lemon zest into the sugar, applying gentle pressure as you rub. Continue rubbing until the lemon zest is evenly distributed throughout the sugar and the sugar becomes fragrant with lemon aroma.
Add flour to the lemon sugar mixture and whisk together until there are no lumps.
Pour in the lemon juice, egg, and egg yolks into the sugar mixture and whisk until smooth.
Pour the lemon filling over the slightly cooled crust, spreading it evenly.
Return the baking dish to the oven and bake for an additional 20 minutes, or until the filling is set and the edges are lightly golden. The center should jiggle a little but not liquid.
Once baked, remove the dish from the oven and allow them to cool completely in the baking dish. Room temperature should be good!
Once cooled, slowly remove lemon bars by pulling up the sides of the parchment paper and place on a cutting board. Cut into 9 equal squares, dust with powdered sugar, and serve.
