Lemon Bars with Shortbread Crust (Thick Squares)

Lemon Bars with Shortbread Crust

These lemon bars have a substantial buttery shortbread base beneath a thick, softly set lemon filling. An 8-by-8-inch pan gives each square two distinct layers and a bright yellow top that needs no dusting.

Prebake the crust so it holds up beneath the wet filling, then bake the bars until the lemon layer is set with just a slight wobble at the center. Cooling and chilling finish the set and make the bars easier to cut into sturdy squares.

Ingredients for Lemon Bars

Shortbread crust

• 1 1/2 cups all-purpose flour (180g)
• 1/2 cup (1 stick) unsalted butter, softened (115g)
• 1/3 cup powdered sugar (40g)
• 1/4 teaspoon fine salt

Lemon filling

• 1 1/2 cups granulated sugar (300g)
• 1/4 cup all-purpose flour (30g)
• 4 large eggs
• 2/3 cup fresh lemon juice, from approximately 3 to 4 lemons
• 2 teaspoons finely grated lemon zest, from approximately 2 lemons

Optional for serving: 1 to 2 tablespoons powdered sugar. Measure the juice rather than relying on the lemon count; yields vary.

How to Make Lemon Bars with Shortbread Crust

1. Prepare the pan: Heat the oven to 350°F (175°C) with a rack near the center. Line an 8-by-8-inch baking pan with parchment, leaving overhang on two sides for lifting out the bars.
2. Make the shortbread: Mix the softened butter, crust powdered sugar, and salt. Add the 1 1/2 cups flour and mix just until a cohesive, pressable dough forms. Press it firmly and evenly across the pan bottom and into the corners.
3. Prebake the crust: Bake uncovered for 18 to 22 minutes, checking at 18 minutes. The surface should look set and the edges should be lightly golden. Keep the oven on.
4. Whisk the filling: Near the end of the crust bake, whisk the granulated sugar with the 1/4 cup filling flour to disperse the flour. Whisk in the eggs, then the lemon juice and zest, until evenly yellow with no visible flour lumps.
5. Fill and bake: Pour the filling over the warm crust and return the pan to the oven. Bake uncovered for approximately 25 to 28 minutes, starting to check at 23 minutes. The surface and edges should look set, with only a slight wobble at the center when the pan is gently nudged.
6. Cool and chill: Cool in the pan until no longer warm, approximately 1 hour. Refrigerate for at least 2 hours, until the filling is firm.
7. Cut into squares: Lift out the chilled slab using the parchment and cut into 16 squares, wiping the knife between cuts. Serve undusted to show the lemon tops and cut layers, or add a light dusting of powdered sugar just before serving.

Yield: 16 square bars. Prep: 20 minutes. Bake: about 43 to 50 minutes total. Total: about 4 hours 15 minutes, including cooling and chilling.

How to Tell When Lemon Bars Are Done

The crust should no longer look like raw dough before the filling goes on. Its separate bake helps prevent a soft, underdone base.

After the second bake, a small wobble confined to the center is fine; the filling firms further as it cools and chills. If it moves in a visibly liquid ripple, give it more time. Waiting until the center is completely rigid can leave the filling dry. Keep the 8-by-8-inch pan size for the intended layer depth; a larger pan makes thinner bars that bake differently.

How to Cut Clean, Thick Squares

Cooling removes the warmth, but chilling firms the lemon layer enough for defined cuts. Once the bars have chilled for at least 2 hours, lift out the slab and use a sharp knife, wiping it between cuts so the filling does not smear across the shortbread. The squares should hold their shape if loosely stacked for serving.

Storing and Freezing Lemon Bars

Keep the bars covered in the refrigerator for 3 to 4 days. The crust may soften somewhat during storage. Serve the bars chilled or let the cut squares stand briefly before serving.

To freeze, place fully chilled, cut, undusted bars in a single layer until firm. Wrap them or separate them with parchment, and freeze for up to 3 months. Thaw in the refrigerator. If using powdered sugar, dust the bars just before serving so it does not dissolve into the moist surface.

For another fruit dessert with a buttery crust, try this French apple tart.

Nutrition

Approximate nutrition per square, based on 16 bars without the optional powdered-sugar topping: 200 calories, 3g protein, 7g fat, and 32g carbohydrates. Approximate values per 100g of finished bars: 340 calories, 5g protein, 12g fat, and 54g carbohydrates. Values are estimates; finished weight and ingredient brands will affect them.