Preheat your oven to 375 degrees and line a 9 x 13 pan with parchment paper and set aside.
Start with your shortbread crust. In a large mixing bowl, add flour, powdered sugar, salt, lemon zest and cold butter cut into little pieces. Using your hands or an electric mixer, cut the butter into the dry ingredients until it all looks like crumbs and then keep mixing until a dough forms. Take that dough and evenly press into the bottom of your baking pan. Bake your shortbread crust for 20 minutes.
While your crust is baking, add eggs, sugar, flour, baking powder, lemon juice and lemon zest to a large mixing bowl and mix well until your lemon curd mixture is loose and a bit frothy. Once your crust is done, remove from the oven and pour your lemon curd mix on top of the crust. Reduce your oven temp to 350 degrees and bake your Easy Classic Lemon Bars for anther 25 minutes.
Remove from the oven and move pan to a wire rack to cool. Wait 30 minutes and then remove the lemon bars from the pan by picking up the edges of the parchment paper and carefully (they are super gentle at this point!) to baking sheet. Move your baking sheet to the refrigerator to chill for 1 hour before dusting them with powdered sugar. Lemon Bars can be stored in an airtight container in the refrigerator.