For the Shortbread Crust:

• Cooking spray
• 16 tablespoons (2 sticks) unsalted butter at room temperature, softened (see Note 1)
• 1/2 cup granulated sugar
• 1 teaspoon vanilla bean paste or 1-1/2 teaspoon vanilla extract
• 2 cups all-purpose flour
• 3/4 teaspoon fine sea salt

For the Lemon Filling:

• 1 1/2 cups granulated sugar
• 3 tablespoons all-purpose flour
• 4 to 5 large fresh lemons (to yield 2 teaspoons zest and 2/3 cup juice; see Note 2 for juicing tips)
• 4 large eggs
• 1/4 teaspoon lemon extract (optional, for extra lemon punch; see Note 3)
• 1/3 cup heavy cream
• 1/4 teaspoon fine sea salt

For Topping:

• Powdered sugar for dusting

• Prepare the Pan: Line a ceramic 9×13-inch baking pan with parchment paper, leaving a generous overhang on the long sides for easy lifting. Lightly spray the parchment paper with cooking spray and set the pan aside.
• Make the Shortbread Crust: In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), beat the softened butter and 1/2 cup granulated sugar until the mixture is light, smooth, and creamy, which typically takes about 2-4 minutes. Scrape down the sides of the bowl as needed to ensure even mixing. Add the 3/4 teaspoon of salt and the vanilla bean paste (or extract); mix until fully integrated. Finally, gradually add the 2 cups of all-purpose flour. Mix on low speed until a thick, cohesive dough forms. If the dough feels too soft or sticky, incorporate an additional 1 to 3 tablespoons of flour until it’s easy to handle.
• Bake the Crust: Firmly press the prepared dough evenly into the bottom of your lined baking pan, extending it about 1/2 inch up the sides. It’s crucial to press the crust tightly into all edges and corners to create a barrier that prevents the lemon filling from seeping underneath. Place the pan in the freezer for 15 minutes to firm up. Meanwhile, preheat your oven to 350°F (175°C). After freezing, press the edges of the crust one more time to ensure a super tight seal. Bake the crust for 22–25 minutes, or until the edges are lightly golden brown and the center is set.
• Prepare the Lemons: While the crust bakes, zest your lemons to obtain 2 teaspoons of bright yellow zest, being careful to avoid the bitter white pith. Then, juice the lemons to yield 2/3 cup of fresh lemon juice. (Refer to the “How to Get More Juice” section above for tips on maximizing juice extraction).
• Make the Lemon Filling: In a blender, combine the remaining 1½ cups granulated sugar with the lemon zest. Pulse about 5 times (for 1 second each pulse) to gently break down the zest and infuse its oils into the sugar, intensifying the lemon flavor. Add the remaining 3 tablespoons of flour, the measured lemon juice, the remaining 1/4 teaspoon of salt, the 4 large eggs, and the heavy cream. If using, add the 1/4 teaspoon of lemon extract. Blend the mixture for no more than 10 seconds, or just until it appears smooth and well combined. Be careful not to overblend, as this can introduce too many air bubbles into the filling. Give the mixture a quick stir with a spatula to ensure everything is incorporated and set aside.
• Assemble and Bake: Carefully remove the partially baked crust from the oven. Stir the lemon filling mixture one last time with your spatula, then slowly and evenly pour it directly over the hot shortbread crust. Return the pan to the oven and bake for an additional 20–25 minutes, or until the center of the lemon custard is just set and jiggles slightly (like firm Jell-O or pudding), and the top looks matte, not wet.
• Cool and Serve: Allow the baked lemon bars to cool completely at room temperature for at least 2 hours. Once cooled to room temperature, transfer the pan to the refrigerator and chill for a minimum of 2 more hours, or preferably until fully set (this can be done overnight). Once firm, use the parchment paper overhang to carefully lift the entire slab of lemon bars out of the pan. For clean, sharp slices, use the hot knife cutting method described in the “Quick Tip” section above. Finally, dust generously with powdered sugar through a fine sieve just before serving. Store any leftover lemon bars in an airtight container in the refrigerator.

Note 2: When zesting lemons, ensure you only grate the bright yellow part of the skin, completely avoiding the bitter white pith beneath. A microplane is ideal for this. Using a good citrus juicer will make the juicing process significantly easier and more efficient.

Note 3: Lemon extract is an optional ingredient that adds an intensified burst of natural citrus flavor. You can typically find it in the baking aisle of your grocery store, often located near vanilla extract.

Storage: Fridge: Cover the cooled lemon bars tightly and store them in an airtight container in the refrigerator for 4–6 days to maintain freshness and texture. Freezer: To freeze, cut the chilled bars into individual servings and place them on a parchment-lined baking tray until solid (this usually takes 2–3 hours). Once frozen solid, wrap each bar individually in plastic wrap, then transfer them to a freezer-safe bag or airtight container. They will keep well in the freezer for up to 3 months.

Nutrition Information (Approximate)