Step 1: Preheat and Prepare

Preheat your oven to 375°F (190°C). Grease a 9×13-inch glass baking dish with butter or cooking spray and set it aside. Using a glass dish ensures even baking and prevents the bars from becoming too crisp on the edges.

Step 2: Make the Crust

In a medium-sized mixing bowl, combine the butter, flour, powdered sugar, and salt. Use a pastry cutter or a spatula to mix the ingredients until they form a crumbly, dough-like texture. If you don’t have a pastry cutter, a fork or your hands will work just as well.

Press the mixture evenly into the prepared baking dish, making sure it covers the bottom completely. Try to create an even layer so the crust bakes uniformly.

Step 3: Bake the Crust

Place the baking dish in the preheated oven and bake for 20 minutes. The crust should be set but not browned. Overbaking at this stage can cause the crust to become too crisp, so watch it carefully.

Step 4: Prepare the Lemon Filling

While the crust is baking, prepare the lemon layer. In a medium-sized bowl, beat the eggs, lemon juice, granulated sugar, and flour together using a hand mixer or whisk. Mix until the ingredients are well combined and slightly frothy. This aeration helps create a light and smooth texture in the filling.

Step 5: Assemble and Bake

Once the crust has finished baking, remove it from the oven and immediately pour the lemon mixture over the warm crust. This helps the filling adhere properly and prevents separation between layers.

Return the dish to the oven and bake for an additional 22-24 minutes. The lemon bars are done when the edges are slightly golden and the center is set. If you gently shake the pan, the filling should not wobble. Overbaking can cause the bars to become rubbery, so check frequently as the baking time nears completion.

Step 6: Cool and Serve

Allow the lemon bars to cool completely in the pan. This step is crucial for setting the filling. Once cooled, sift powdered sugar over the top for a classic finishing touch. Use a sharp knife to cut them into squares or rectangles. For cleaner slices, wipe the knife with a damp cloth between cuts.