Old Fashioned Lemon Squares Recipe
This Old Fashioned Lemon Squares Recipe is made with a delicately sweet and buttery shortbread crust with a creamy and zesty lemon custard filling baked on top, finished off with a burst of lemon glaze and a dusting of powdered sugar! They are simple enough for a Tuesday brunch but elegant enough for a wedding!
Turn these lemon bars into a cake with my delicious and moist Lemon Bar Cake recipe! Or if you’re looking for a delicious lemon bar-inspired cookie, then some must-try recipes are my Lemon Powdered Sugar Cookies and my ultra soft Lemon Crinkle Cookies. If you love the lemon and shortbread combination, try my Lemon Shortbread Cookie Recipe.
Why This Recipe Works
- Looks fancy but is ultra simple. I feel like these old fashioned lemon bars are such a fancy dessert! I picture them being served on fancy plates with tiny forks and gloved hands. The beauty about these classic lemon bars, though, is while it looks super fancy, this easy lemon bars recipe takes minimal effort. Plus, these lemon bars are so yummy and light, just ditch the tiny fork and take one BIG bite!
- Deliciously tart lemon filling. These are the best lemon squares! The lemon filling is made with fresh lemon juice and fresh lemon zest. Then, to top things off, we add extra lemon flavor with a delicious lemon glaze on top!
Ingredient Notes
- Unsalted Butter: The butter/flour combination will give us the shortbread-style crust.
- Flour: Use regular, all-purpose flour. Although it will feel super crumbly when you are mixing the shortbread crust dough, it will come together when you are pressing it into the pan. We also use a bit of flour in the lemon bars filling to help provide a bit of structure.
- Powdered Sugar: To provide the crust with a bit of sweetness. Use powdered sugar over granulated for a smoother crust texture.
- Granulated Sugar: Use granulated sugar for the lemon squares filling. Because we are using a very tart and sour citrus, we need a bit of sugar to counter that.
- Baking Powder: This will help the custard stay light as it’s baking so it isn’t too dense.
- Eggs: Eggs are the key ingredient for making our luscious lemon filling a delicious custard!
- Lemon Juice: Gotta get that delicious lemony flavor, so the lemon juice is our liquid ingredient for the custard. I love my easy handheld lemon juicer because it’s quick and simple to use — which does mean you should use fresh lemons!
- Lemon Zest: Be sure to use a lemon zester and get fresh lemon zest! The zest gives a sharper and distinct lemon flavor that will penetrate through each bar.
Step-by-Step Instructions
- Make the easy shortbread crust. Preheat the oven to 350ºF. To a medium bowl, add 1/2 cup softened butter, 1 cup all-purpose flour, and 1/4 cup powdered sugar. Mix with hand beaters until combined (about 30 seconds) or use a fork to combine. The mixture will be dry and crumbly.
- Press the dough into a prepared pan. Line an 8×8-inch square pan (I use a metal pan.) with parchment paper (with the paper coming up the sides for easy removal). Press the shortbread crust mixture into the bottom of the pan.
- Bake crust. Bake the shortbread crust for 15 minutes. Remove and let cool while you make the lemon filling. Keep the oven at 350ºF.
- Make the lemon bar filling. To a medium bowl, add 1 cup granulated sugar, 2 T all-purpose flour, and 1/2 tsp baking powder. Whisk to combine. Then add 2 eggs, 2 tablespoons of lemon juice and the lemon zest from 1 large lemon. Whisk to combine.
- Pour filling on top of the warm crust. Pour the lemon mixture on top of the baked crust. Bake for 20-22 minutes or until the filling is set and the edges are golden brown. Remove from the oven and let cool for 10 minutes in the pan.
- Add the lemon glaze. Combine 1/2 cup powdered sugar and 1 T lemon juice in a small bowl. Drizzle the glaze on top of the lemon bars. The sprinkle the glazed lemon bars with powdered sugar.
- Slice and serve. Once the bars have cooled completely in the pan, grab the parchment paper, and pull the old fashioned lemon squares out of the pan. The slice and serve. Enjoy!
Recipe Tips
Line the pan with parchment paper so that the parchment comes up the sides. This will make removing the lemon bars much easier! When I took the pictures, I didn’t line with parchment, and honestly I should have!
The shortbread crust will not come together like a dough. As you’re pressing it into the pan the crust will come together.
Though the glaze is optional, I love glazed lemon bars because it adds a bit more lemon flavor right onto the tops of your bars — so you get a delicious burst of lemon the moment the dessert hits your mouth. It also makes the top of the bars extra soft as the glaze seeps into the bars — which I love!
However, the bars have a great balance of lemon and sweet flavors without the glaze. It’s really just up to you!
You don’t need too much powdered sugar dusting on top — just enough to give it this old fashioned lemon squares recipe a fancy finish!
These homemade lemon bars are perfect for serving at bridal showers, baby showers, brunches, Sunday afternoons, Wednesday evenings when the craving hits … basically any time!
Make Ahead, Storing, and Freezing
You can make lemon bars ahead of time and store them in the fridge in an airtight container for a day or two prior to serving.
Store any leftovers of this old fashioned lemon squares recipe in an airtight container at room temperature for 3-4 days.
When freezing lemon bars, simply follow the recipe until the lemon bars are baked. Don’t put on the powdered sugar and just let the bars cool completely. Once cooled, remove them from the pan, cut them, and then place them a half inch or more apart on a cookie sheet.
Let sit in the freezer for about 30 minutes or until firm and just frozen. Remove from the freezer and wrap each lemon bar individually in plastic wrap, then store in a ziplock bag for up to 3 months.
Remove and let thaw before making the glaze, topping the bars and then sprinkling with powdered sugar.
While you can freeze the lemon bars in the pan (or in an 8×8-inch block of bars), it’s important to wrap in plastic wrap and then store in a ziplock bag and I don’t typically have ziplock bags big enough for the entire 8×8-inch pan/dessert.
Recipe FAQs
Custard is a cooked mixture of eggs and cream. Custards can be adapted a variety of ways as well as cooked in different ways. If you watch the Great British Baking Show (cheers to you, it’s my fav) you’ll recognize the term used in reference to tarts (as in a custard tart), a crème anglaise (which is a classic vanilla custard) or a crème patissière (which is a boiled custard).
Custards can have flour added to them, as well as different flavorings, and they can also be baked in the oven or on the stovetop.
Fun fact: quiches are technically custards since you typically make a quiche with cream added to the eggs! Try out my Spinach Quiche Recipe. You can learn more about custards at The Spruce Eats.
This recipe is not gluten free. The shortbread crust is made with flour; the lemon custard filling also has a bit of flour in it. You can try substituting all-purpose flour with gluten-free flour, but I’ve never made with with GF flour, so I can’t guarantee it will turn out or taste at all the same. Good luck!
The lemon curd filling will look set on the top and the edges are golden brown. Don’t over bake! The custard filling should jiggle slightly, but not be runny.
Let these delicious lemon bars cool for up to 10 minutes before adding the glaze (optional, but worth it!) and then dusting with the powdered sugar.
Since the shortbread crust and the lemon custard filling are both baked, you can store any leftover lemon bars at room temperature. However, everything will last longer if stored in the fridge. So feel free to store them in the fridge if desired.
Wait until the lemon bars have cooled completely in the pan. Cutting cooled bars will help the creamy lemon filling to set so it doesn’t go lax when cut while hot or warm. This will also give you clean slices.
The easiest way to cut your lemon bars is to pull the whole sheet of lemon bars out of the pan before cutting. This is why lining your pan with parchment paper is a huge winner! Pull the 8×8-inch square of lemon bars out of the pan. Then, using a sharp knife (and when the bars have cooled completely), cut the bars into squares. Enjoy!
If your classic lemon bars are runny, then they didn’t get baked long enough.
Cracking can come from over beating your lemon custard filling mixture or in a drastic change of temperature (such as baking at too high of a temperature or if you take them out of the oven and place them in the fridge to speed up the chilling process). If your classic lemon bars have cracked, don’t worry! Just cover them with the glaze and powdered sugar.
More of My Family’s Favorite Lemon Desserts
- Lemon Poppy Seed Cake with Cake Mix
- Lemon Zucchini Loaf
- Lemon Ricotta Cookies
- Lemon Raspberry Cake
- Lemon Poppy Seed Scones
Old Fashioned Lemon Squares Recipe
Ingredients
Crust
- 1/2 cup unsalted butter - softened
- 1 cup all purpose flour
- 1/4 cup powdered sugar
Filling
- 1 cup granulated sugar
- 2 tablespoon all purpose flour
- 1/2 teaspoon baking powder
- 2 eggs
- 2 tablespoons lemon juice
- zest from 1 large lemon
Glaze (optional)
- 1/2 cup powdered sugar
- 1 tablespoon lemon juice - may need more for right consistency
Instructions
- Preheat oven to 350°F. Line an 8”x8” square pan with parchment paper so that the parchment comes up the sides. This will make removing the lemon bars much easier.
- In a medium bowl add the softened butter, flour, and powdered sugar. Use hand beaters to mix the mixture for about 30 seconds. Alternatively, you can use a fork and stir everything together. I found the hand mixer to be a bit faster. The mixture will be very dry and crumbly, it will not come together like a dough. Press this crust mixture into to bottom of an 8×8 inch square pan. As you’re pressing it into the pan the crust will come together.
- Bake the crust for 15 minutes at 350°F. Remove from the oven and let cool just slightly while you make the filling.
- In a medium bowl whisk the sugar, flour, and baking powder. Whisk in the eggs, lemon juice, and lemon zest.
- Pour the filling mixture over the baked crust and bake for 20-22 minutes at 350°F or until mixture is set and the edges are golden brown.
- The glaze is optional, if you’d like to glaze the bars whisk the powdered sugar and enough lemon juice to make a glaze that is drizzle-able.
- Remove the bars from the oven and let them cool for 5-10 minutes. Glaze the bars while still warm and sprinkle with extra powdered sugar.
- Store in airtight container for 3-5 days.
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