📖 Instructions

1. Preheat your oven and prepare the pan: First things first, get your oven ready. Preheat it to 350°F (175°C). While it's heating, grab an 8x8 inch (20x20 cm) baking pan. Line the pan with parchment paper, leaving an overhang on two sides. This is a game-changer for easy removal later. Lightly grease the exposed sides of the pan with butter or cooking spray. If you don't have parchment, grease and flour the pan well.
2. Make the shortbread crust: In a medium mixing bowl, whisk together the all-purpose flour, granulated sugar, and a tiny pinch of salt. Now, add the cold, unsalted butter, which you've cut into small cubes. Using a pastry blender, two knives, or even your fingertips, cut the butter into the dry ingredients until the mixture resembles coarse crumbs. The key here is to keep the butter cold, as this creates a tender, flaky crust. Don't overmix!
3. Press the crust into the pan: Pour the crumbly shortbread mixture into your prepared 8x8 inch baking pan. Press it down firmly and evenly across the bottom. You can use the back of a spoon, your clean hands, or even the bottom of a glass to get a nice, compact layer. Make sure it's really packed in there, especially into the corners.
4. Pre-bake the crust: Pop the pan with the crust into your preheated oven. Bake for about 18-20 minutes, or until the edges are just barely turning golden. You're looking for a light, golden color. Remove the pan from the oven and set it aside to cool slightly while you prepare the lemon filling. Keep the oven on!
5. Prepare the lemon filling: In a separate medium mixing bowl, whisk together the large eggs and the remaining granulated sugar until they are well combined and slightly foamy. You don't need to beat them until they're super airy, just enough to combine. Next, whisk in the fresh lemon juice, lemon zest, and the remaining 2 tablespoons of all-purpose flour until the mixture is smooth. The flour helps to give the filling a nice, slightly firm, custard-like texture.
6. Pour and bake the filling: Carefully pour the lemon filling over the warm, pre-baked shortbread crust in the pan. Gently spread it if needed to ensure an even layer. Return the pan to the oven and bake for another 20-25 minutes. The filling should be set and barely jiggle in the center when you gently shake the pan. The edges might look slightly golden. Be careful not to overbake, or the filling can become tough.
7. Cool completely: This step is CRUCIAL for perfectly set lemon bars. Once baked, remove the pan from the oven and place it on a wire rack to cool completely at room temperature. This will take at least 1 to 2 hours. After that, transfer the pan to the refrigerator and chill for at least 2 more hours, or even better, overnight. This chilling time allows the lemon filling to firm up properly, making it easy to cut.
8. Cut and serve: Once thoroughly chilled, use the parchment paper overhang to lift the entire slab of lemon bars out of the pan and onto a clean cutting board. Peel away the parchment paper. Using a sharp, non-serrated knife, trim the edges for a clean presentation (optional, but makes them look professional!). Then, cut the large square into 16 smaller squares. Just before serving, dust generously with powdered sugar for that classic, beautiful finish. Enjoy your tangy, sweet, and perfectly easy lemon bars!