Classic Lemon Bars With Buttery Shortbread Crust

Quick Recipe Version (TL;DR)

• Yield: 16 bars
• Prep Time: 20 minutes
• Cook Time: 40 minutes
• Total Time: 3 hours (includes cooling)

Quick Ingredients

• 2 cups (260 g) all-purpose flour, plus 1/2 cup (60 g) for filling
• 1/2 cup (60 g) powdered sugar, plus extra for dusting
• 1/4 cup (50 g) granulated sugar
• 1/4 tsp fine sea salt
• 1 cup (226 g) unsalted butter, cold, cubed
• 1 tsp vanilla extract (optional, for crust)
• 6 large eggs, room temperature
• 2 cups (400 g) granulated sugar (for filling)
• 1 cup (240 ml) fresh lemon juice (about 4–5 lemons)
• Finely grated zest of 3 lemons
• 2 tbsp (30 ml) heavy cream or whole milk (optional, for silkier custard)

Do This

• 1. Preheat oven to 350°F (175°C). Line a 9×13-inch pan with parchment, leaving overhang.
• 2. Pulse crust ingredients (flour, sugars, salt, butter, vanilla) in a food processor or cut together until crumbly.
• 3. Press crust evenly into pan. Bake 18–20 minutes, until lightly golden at edges.
• 4. While crust bakes, whisk eggs, sugar, flour, lemon zest, lemon juice, salt, and cream until smooth.
• 5. Pour filling over hot crust. Bake 18–22 minutes, just until center is set and no longer jiggly.
• 6. Cool completely, chill 1–2 hours, dust with powdered sugar, then slice into 16 bars.

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Why You’ll Love This Recipe

• Perfect contrast: buttery, tender shortbread crust under a bright, silky lemon custard layer.
• Balanced flavor: fresh lemon juice and zest give a tangy bite without being overwhelmingly sour.
• Make-ahead friendly: bars slice more cleanly and taste even better after chilling.
• Party-ready: easy to transport, cut, and serve for potlucks, picnics, and holidays.

Grocery List

• Produce: 4–5 lemons (for 1 cup juice and zest of 3 lemons)
• Dairy: 1 cup unsalted butter, 2 tbsp heavy cream or whole milk (optional)
• Pantry: All-purpose flour, powdered sugar, granulated sugar, fine sea salt, vanilla extract (optional)

Full Ingredients

Buttery Shortbread Crust

• 2 cups (260 g) all-purpose flour
• 1/2 cup (60 g) powdered sugar
• 1/4 cup (50 g) granulated sugar
• 1/4 tsp fine sea salt
• 1 cup (226 g) unsalted butter, cold, cut into small cubes
• 1 tsp vanilla extract (optional, but adds lovely flavor)

Bright, Silky Lemon Custard Layer

• 6 large eggs, at room temperature
• 2 cups (400 g) granulated sugar
• 1/2 cup (60 g) all-purpose flour
• Finely grated zest of 3 lemons (about 2–3 tbsp)
• 1 cup (240 ml) freshly squeezed lemon juice (from about 4–5 lemons)
• 1/4 tsp fine sea salt
• 2 tbsp (30 ml) heavy cream or whole milk (optional, for extra silkiness)

For Finishing

• 1/4–1/2 cup (30–60 g) powdered sugar, for dusting
• Thin lemon slices or extra zest, for garnish (optional)

Step-by-Step Instructions

Step 1: Prep your pan and preheat the oven

Preheat your oven to 350°F (175°C) with a rack in the center position. Lightly grease a 9×13-inch (23×33 cm) baking pan, then line it with parchment paper, leaving a 1–2 inch overhang on the long sides. This overhang acts as a sling so you can lift the bars out easily for clean slicing. Lightly grease the parchment as well.

Set the prepared pan aside while you make the shortbread crust.

Step 2: Make the buttery shortbread crust

In a large bowl, whisk together the flour, powdered sugar, granulated sugar, and salt until well combined. Add the cold, cubed butter and the vanilla extract (if using).

Using a pastry cutter, two knives, or clean fingertips, cut or rub the butter into the dry ingredients until the mixture looks like coarse, even crumbs and no large chunks of butter remain. The mixture should hold together when pressed between your fingers. If you have a food processor, you can pulse the mixture in short bursts until this crumbly texture is achieved.

Step 3: Press and bake the crust

Tip the crumbly crust mixture into the prepared pan. Use your hands or the flat bottom of a measuring cup to press it firmly and evenly into the bottom of the pan, making sure the corners are filled and the surface is as level as possible. A firmly packed crust helps support the soft lemon layer.

Bake the crust at 350°F (175°C) for 18–20 minutes, or until the edges are just turning lightly golden and the surface looks set and matte, not wet. While the crust bakes, prepare the lemon custard filling.

Step 4: Whisk together the lemon custard filling

In a large mixing bowl, whisk the eggs until they’re well broken up and slightly frothy. Add the granulated sugar and whisk until the mixture looks thickened and slightly lighter in color, about 30–60 seconds by hand.

Sprinkle the flour evenly over the egg-sugar mixture and whisk until no dry pockets remain. Add the lemon zest, lemon juice, salt, and heavy cream or milk (if using). Whisk until the mixture is completely smooth and well combined. Try not to whisk so vigorously that you create a lot of foam; a gentle but thorough whisk is perfect.

Set the filling aside. If foam forms on the surface, you can skim it off with a spoon for the smoothest top.

Step 5: Combine crust and filling, then bake until just set

When the crust is done, carefully remove the pan from the oven but keep the oven on. While the crust is still hot, give the lemon filling a quick stir, then gently pour it over the hot crust, tilting the pan slightly if needed so the filling spreads into an even layer.

Return the pan to the oven and bake at 350°F (175°C) for 18–22 minutes. The lemon layer is done when the surface looks set and no longer shiny, the edges are just barely starting to pull away from the pan, and the center no longer jiggles in waves when you gently shake the pan. A very slight wobble is okay; it will firm up as it cools. Avoid overbaking, which can make the custard rubbery.

Step 6: Cool, chill, and dust with powdered sugar

Place the pan on a wire rack and allow the lemon bars to cool completely at room temperature, about 1–1 1/2 hours. Once cool, transfer the pan to the refrigerator and chill for at least 1 hour (or up to overnight). Chilling helps the custard set fully and makes slicing much easier.

When ready to serve, use the parchment sling to lift the entire slab of lemon bars from the pan onto a cutting board. Sift a generous layer of powdered sugar evenly over the top. For a neat presentation, you can dust once, slice, then dust again lightly to refresh the top.

Step 7: Slice and serve

Use a long, sharp knife to slice the bars into 16 pieces (4 rows by 4 rows). For the cleanest cuts, wipe the knife with a warm, damp cloth and dry it between each slice. If desired, garnish each bar with a tiny pinch of extra lemon zest or a very thin lemon slice.

Serve chilled or at cool room temperature. The crust will be delicately crisp and buttery, and the lemon layer will be silky, smooth, and brightly flavored.

Pro Tips

• Use fresh lemons: Bottled lemon juice cannot match the brightness and aroma of fresh juice and zest. The zest adds tons of flavor, so do not skip it.
• Do not overbake: Pull the bars from the oven as soon as the custard is set with only a slight wobble. Overbaking leads to a firm, rubbery texture instead of a silky one.
• Chill before slicing: Cooling fully and chilling for at least 1 hour gives cleaner cuts and a custard that holds its shape beautifully.
• Line with parchment: The parchment sling makes it easy to lift out the whole slab and slice neatly, rather than digging awkwardly in the pan.
• Dust just before serving: Powdered sugar can gradually dissolve on the lemon surface. For a picture-perfect finish, dust within an hour of serving.

Variations

• Extra-lemony bars: Add the zest of 1 additional lemon and a few drops of pure lemon extract for an even brighter, more intense citrus flavor.
• Lavender lemon bars: Infuse 1–2 tsp culinary lavender buds in the warm lemon juice for 10 minutes, then strain before adding to the filling for a delicate floral twist.
• Almond shortbread crust: Substitute 1/2 cup (50 g) of the all-purpose flour in the crust with finely ground almonds or almond flour and add 1/4 tsp almond extract.

Storage & Make-Ahead

Store the lemon bars in an airtight container in the refrigerator for up to 4–5 days. Separate layers with parchment paper to prevent sticking. For the freshest look, dust with powdered sugar just before serving.

To make ahead, you can bake the bars completely (without powdered sugar), cool, cover tightly, and refrigerate overnight. Slice and dust the next day. Lemon bars also freeze well: freeze the sliced bars on a baking sheet until firm, then transfer to a freezer-safe container with parchment between layers. Freeze for up to 2 months. Thaw in the refrigerator, then dust with powdered sugar before serving.

Nutrition (per serving)

Approximate values per bar (1 of 16): about 320 calories; 4 g protein; 43 g carbohydrates; 15 g fat; 9 g saturated fat; 0.5 g fiber; 30 g sugar; 160 mg sodium. These values are estimates and will vary based on specific ingredients and portion sizes.