Lemon bars have a buttery shortbread crust beneath a thick, sweet-tart lemon filling. Fresh juice and zest give the filling its citrus flavor, and thorough cooling helps the generous squares hold their shape.
Bake the slab in a nine-by-thirteen-inch pan and cut a three-by-four grid for twelve large bars. Plan ahead: active preparation is about twenty minutes, but cooling the crust, cooling the filling, and chilling the finished slab bring the estimated total to four hours and forty-five minutes.
On This Page
Why This Recipe Works
The crust for these lemon bars bakes first to give the wet filling a firm base. Creamed butter and sugar form a tender shortbread layer without needing baking powder. Eggs set the lemon mixture, while flour helps it hold a sliceable shape. Cooling and refrigeration firm the filling further, so cutting straight from the oven gives a much softer result.
Ingredients
For lemon bars with a tender base, use softened unsalted butter for the crust and six extra-large eggs for the filling. Measure the flour separately: two cups belong in the base and one cup in the lemon mixture. The sugar amounts are also separate, with a half-cup in the crust and three cups in the filling. Zest the lemons before juicing them, avoiding the bitter white pith.
Shortbread Crust
- 1 cup unsalted butter, softened
- 1/2 cup granulated sugar
- 2 cups all-purpose flour
- 1/8 teaspoon salt
- Cooking spray, for exposed pan sides
Lemon Filling
- 6 extra-large eggs, room temperature
- 3 cups granulated sugar
- 2 tablespoons lemon zest, finely grated
- 1 cup fresh lemon juice
- 1 cup all-purpose flour
- Powdered sugar, for dusting
How to Make lemon bars
1. Make an even shortbread base. Heat the oven to 350°F. Line a nine-by-thirteen-by-two-inch pan with parchment, leaving an overhang, and lightly grease the exposed sides. Cream the softened butter with the half-cup sugar for two to three minutes until smooth. Mix in the two cups flour and the salt just until combined. Press the dough evenly across the base with a low half-inch edge; thick ridges bake differently from the center.
2. Bake and cool the crust. Bake the base for fifteen to twenty minutes until its edges are lightly golden and the surface looks set. Place the pan on a rack for about thirty minutes so the crust cools before the filling goes on. Keep the oven at 350°F. A dark brown base will become firmer during its second bake, so stop at a pale golden color.
3. Whisk and bake the filling. Whisk the eggs, three cups sugar, lemon zest, and lemon juice, then whisk in the remaining cup of flour until no large flour lumps remain. Pour over the cooled base and return the pan to the oven for thirty to thirty-five minutes. The filling should be set, with at most a gentle center jiggle rather than a loose liquid wave. If checking with a thermometer, look for a minimum of 160°F in the egg layer. Avoid baking until the entire surface is rigid and deeply browned.
4. Cool, chill, and cut. Cool the pan on a rack for about an hour, then refrigerate for at least two hours until cold and firm. Get the baked bars into the refrigerator within two hours of leaving the oven. Lift out with the parchment, dust lightly with powdered sugar, and cut twelve large squares. Wipe the knife between cuts to keep the edges clean; dusting just before serving limits a damp sugar surface.
How to Serve
Serve the lemon bars chilled or let individual bars sit briefly at room temperature before eating. Twelve pieces are generous dessert portions; cutting each square in half gives twenty-four smaller servings. Dust only the pieces being served if you want the powdered sugar to stay visible.
Storage
Keep the lemon bars covered in the refrigerator for up to three days. Refrigerate the baked slab within two hours after it leaves the oven, and keep serving portions out for no more than two hours. Freeze undusted, chilled pieces between layers of parchment for up to two months. Thaw in the refrigerator and add powdered sugar when serving. See federal cold-storage guidance for refrigerated foods.
Tips and Variations
- Use extra-large eggs and softened, not melted, crust butter.
- Press the shortbread into an even thickness with a low border.
- Look for a set filling with a gentle jiggle, not a wet wave.
- Chill the slab completely and wipe the knife between cuts.
Frequently Asked Questions
Can I use bottled lemon juice?
For lemon bars, fresh juice gives a brighter flavor and supplies lemons for the zest. Bottled juice can taste flatter in this citrus-forward filling.
Why does the powdered sugar disappear?
Moisture from the filling dissolves it over time. Dust close to serving rather than before storing.
Can I use a smaller pan?
A smaller pan makes thicker layers and changes their baking times. Use the listed pan size for this batch.
Are twelve bars the only cutting option?
No, cut smaller rectangles for a dessert tray. Keep the total slab yield in mind when changing the serving count.
Why are my cuts ragged?
The warm center of lemon bars smears on the knife. Chill thoroughly and clean the blade after each cut.
More Recipe Ideas
Lemon Bars with Shortbread Crust
Ingredients
Shortbread Crust
- 1 cup unsalted butter softened
- 1/2 cup granulated sugar
- 2 cups all-purpose flour
- 1/8 teaspoon salt
- Cooking spray for exposed pan sides
Lemon Filling
- 6 extra-large eggs room temperature
- 3 cups granulated sugar
- 2 tablespoons lemon zest finely grated
- 1 cup fresh lemon juice
- 1 cup all-purpose flour
- Powdered sugar for dusting
Instructions
Make the Crust
- Preheat oven to 350°F. Line a 9×13×2-inch pan with parchment overhang and lightly grease the exposed sides.
- Cream butter and 1/2 cup sugar for 2–3 minutes until smooth. Mix in 2 cups flour and salt, then press evenly into the pan with a low 1/2-inch border.
- Bake at 350°F for 15–20 minutes until the edges are pale golden. Cool on a rack about 30 minutes; keep the oven at 350°F.
Fill and Chill
- Whisk extra-large eggs, 3 cups sugar, lemon zest, and lemon juice. Whisk in the filling’s 1 cup flour until smooth and pour over the cooled crust.
- Bake at 350°F for 30–35 minutes until set with a slight center jiggle and no liquid wave; the egg filling should reach at least 160°F.
- Cool on a rack about 1 hour, then refrigerate at least 2 hours until firm. Lift out, dust with powdered sugar, and cut 12 large squares.
Notes
- Refrigerate the baked slab within 2 hours of oven removal; store covered for up to 3 days.
- Freeze undusted bars up to 2 months, separated with parchment.
- Thaw refrigerated and add the sugar dusting when serving.
