Old-Fashioned Lemon Squares

These old-fashioned lemon squares start with a buttery shortbread crust, a bright and tangy lemon curd filling, and a dusting of powdered sugar on top. With just 7 ingredients and 10 minutes of prep, they’re one of the easiest baked desserts you’ll make all spring.

Before You Get Started

This recipe traces back to the VeryVera cookbook and the classic Southern lemon bars that have shown up in community cookbooks for generations. A few things to keep in mind before you start:

• Use a glass or ceramic baking dish. Metal pans can react with the lemon filling and leave a faint metallic aftertaste. Plan for this before you start since it affects the final flavor.
• Bake the crust until golden brown. An underbaked crust goes soggy once the filling is added. Look for real color before the filling goes on.
• Cool completely before slicing. Room temperature for about 1 hour, then refrigerate for at least 2 more hours. Cold bars slice cleanly; warm ones don’t.

How to Make Lemon Squares

These classic bars come together in two layers: a shortbread crust and a lemon curd filling. The hands-on time is minimal; the hardest part is waiting for them to cool.

Step 1: Prep the Pan and Preheat

Preheat the oven to 350°F. Grease and flour a 9×13-inch glass baking dish, or line it with parchment paper leaving an overhang on both sides. 

The parchment method makes it easy to lift the whole slab out for clean slicing later.

Step 2: Make the Shortbread Crust

In a large bowl, stir together the melted butter, flour, and confectioners’ sugar until fully combined. The mixture will look crumbly at first but comes together into a soft dough. 

If you’re using unsalted butter, add about 1/2 teaspoon of salt to the crust at this point.

Press the dough into an even layer in the prepared pan. The flat bottom of a measuring cup works well for getting a smooth surface. 

Bake for 15 to 20 minutes, until the crust is a light golden brown. Don’t pull it early. That golden color means it’s set and ready to hold up under the filling.

⇢ Prefer a graham cracker base? My Easy Lemon Bars skips the oven entirely and uses a creamy no-bake filling instead.

Step 3: Make the Lemon Filling

While the crust bakes, whisk together the granulated sugar, flour, and baking powder in a large bowl. Add the eggs, fresh lemon juice, and lemon zest. Whisk until completely smooth.

Use freshly squeezed lemon juice here, not bottled. The zest matters just as much. It carries the essential oils and bright citrus flavor that make these bars taste fresh rather than flat. When zesting, stick to the outer yellow layer only. The white pith underneath is bitter and will dull the flavor. 

For a more pronounced lemon taste, add an extra teaspoon of zest. It won’t change the structure of the filling, just the intensity.

Step 4: Pour and Bake

Pour the filling over the hot crust as soon as it comes out of the oven.

Return the pan to the oven and bake for about 25 minutes.

The filling is done when the center no longer jiggles when you gently shake the pan. The edges set first; the top should look matte rather than shiny when fully baked. 

If you notice small white bubbles on top after baking, that’s completely normal. A dusting of powdered sugar takes care of them.

Step 5: Cool and Slice

Cool the bars on a wire rack at room temperature for about 1 hour, then refrigerate for at least 2 more hours. 

Once fully chilled, dust generously with confectioners’ sugar and slice into squares. For the cleanest cuts, use a sharp knife and wipe the blade between each slice.

Want to Mix It Up?

• Lime Bars: Swap the lemon juice and zest for an equal amount of fresh lime juice and lime zest.
• Lemon Blueberry Squares: Fold about 1 cup of fresh blueberries into the filling before pouring it over the crust.
• Lemon Basil Bars: Add 2 tablespoons of finely chopped fresh basil to the filling for a version that’s a little unexpected and really lovely.

Storage

Refrigerator: Store in an airtight container for up to 1 week. These bars actually improve after the first day as the filling firms up and the flavors deepen, which makes them a great make-ahead dessert.

Freezer: Freeze before dusting with powdered sugar. Wrap tightly in plastic wrap or foil and store for up to 3 months.

Thawing: Thaw overnight in the refrigerator. Dust with fresh powdered sugar just before serving.

Frequently Asked Questions

Is it better to bake lemon squares in a glass or metal pan?

Glass or ceramic is the better choice. Lemon juice is acidic, and metal pans can react with that acid during baking, sometimes leaving a faint metallic aftertaste. Glass and ceramic are non-reactive, so the flavor stays clean. If metal is all you have, a well-coated pan reduces the risk.

Why are my lemon squares soggy?

A soggy filling almost always comes from an underbaked crust. The shortbread needs to be golden brown before the filling goes on. If it’s pale or soft, it won’t hold up under the wet lemon custard. Bake the crust until it has real color, then pour the filling over it while it’s still hot.

Do lemon squares need to be refrigerated?

They’re fine at room temperature for up to 24 hours, but refrigerate them as soon as possible. Keeping them chilled prevents bacterial growth and keeps the filling firm and easy to slice. Pull them out 20 to 30 minutes before serving if you prefer them closer to room temperature.

Can I use a different pan size?

Yes, but it will change the thickness of both layers and the baking time. A smaller pan like an 8×8-inch dish produces thicker bars and needs a longer bake for the filling to set. A larger pan produces thinner bars that set more quickly. Watch the doneness cues rather than relying strictly on the timer.

I’ve tried other recipes this is my favorite!!

– Michael

More Easy Spring Desserts

• Lemon Cream Cheese Pound Cake
• Strawberry Cobbler
• Strawberry Shortcake Cake
• Strawberry Cake with Cream Cheese Frosting
• Lemon Bundt Cake
• Lemon Bars with Cake Mix