The Best Gluten-Free Lemon Bar Recipe You’ll Ever Make

Get ready to make the best gluten-free lemon bars ever, complete with a thick custardy citrus filling set atop a sweet and crumbly shortbread crust. You won’t miss the gluten, I promise! The recipe was updated in January 2024 to add more lemon filling on top and to improve the photos. This post contains affiliate links. Please see my disclosures.

Following a strict gluten-free diet can be challenging, especially when trying to navigate the world of gluten-free baking.

When you have celiac disease, non-celiac gluten sensitivity, or gluten intolerance, baking can feel like a contact sport when you can’t use gluten, a protein found in wheat (wheat flour), rye, and barley. Gluten is the “glue” that holds baked goods together.

Today, however, I’m going to show you how to make a classic lemon bar recipe that will make you love dessert again – especially lemon desserts.

These lemon bars are bursting with citrusy goodness, and they, simply put, melt in your mouth. They are proof that living a gluten-free lifestyle doesn’t mean you have to miss out on your favorite sweet treats.

This recipe is based on my mother-in-law’s recipe for traditional lemon bars, which are made with gluten. I took her recipe, made it gluten-free, and added a thicker layer of lemony deliciousness.

The results are excellent, and these gluten-free lemon bars truly look as impressive as they taste!

Ingredients for Making Lemon Bars

These gluten-free lemon squares have both a shortbread bottom and a lemon custard topping.

(1) For the delicious shortbread crust, you’ll need the following ingredients:

Gluten-Free Flour: You’ll need 1 1/3 cups of a gluten-free flour blend, one that contains a mixture of rice flour, starches, and xanthan gum. I use Bob’s Red Mill’s 1-to-1 gluten-free flour blend, but you could use any 1-to-1 gluten-free flour you like.

I have not tested this recipe with almond flour or coconut flour. If you want to bake with these flours, I suggest you find a recipe that uses either or both flours.

Sugar: You’ll need 1/4 cup of granulated white sugar to sweeten the shortbread crust.

Butter: You’ll also need 1/2 cup of softened butter. I sometimes use vegan butter, like Earth Balance buttery sticks, when making a dairy-free option.

(2) For the lemon filling, you’ll need the following ingredients:

Eggs: This recipe requires three large eggs. My prior recipe only called for two eggs, but I noticed that adding an extra egg made the filling more complete and delicious. I don’t have an egg-free version of this recipe, however. Lemon bars are an egg-heavy recipe, so they do not fit well within a vegan diet.

Sugar: You’ll need one full cup of granulated sugar. This is 1/4 cup more than my original recipe and accounts for the extra egg and additional flour required to make an extra tall custardy filling.

Gluten-Free Flour: You’ll need three tablespoons of gluten-free flour. I used Bob’s Red Mill’s 1-to-1 gluten-free flour blend.

Lemons: For this recipe, you’ll use two large lemons or three small lemons. You’ll use both the zest and juice, and you can adjust how much zest and juice you add depending on how lemony you like it. Always use fresh lemons.

Some people use Meyer lemons instead of regular lemons. A regular lemon gives the recipe a tart and tangy taste, while a Meyer lemon is more sweet than tart. You can use either type of lemon in this recipe.

How To Make the Lemon Bar Crust

To make the lemon bar crust, combine all the crust ingredients (flour, sugar, and softened butter) in your standing or handheld electric mixer. Mix the ingredients well using your mixer for about 1-2 minutes. You’ll wind up with a crumbly crust that, when pressed together, will form the solid base for your lemon bars.

Add the crumbly mixture to a greased 8×8″ square glass baking dish. If using a metal 8×8 baking pan, line the bottom with parchment paper and coat the bottom and sides with cooking oil.

Press the mixture in place with your fingers to form an even layer of crust. Use the palms of your hands to help flatten the crust. Below is what the mixture looks like once the crumbs are pressed into a solid foundation.

Before adding the custard filling, par-bake the crust for 17-18 minutes until it’s set, as pictured below.

How to Make the Lemon Bar Filling

While the crust is baking, prepare the lemon bar filling. To do this, combine all the filling ingredients (sugar, eggs, flour, lemon zest, and fresh lemon juice) in a medium or large bowl and whisk until well combined.

Once the crust is par-baked, pour the egg mixture on top of it. Although unnecessary, you can lightly bang the dish against the countertop to eliminate any air bubbles in the egg mixture.

Place the dish back into the oven to continue baking for another 18-20 minutes until the lemon topping is set and the edges are slightly golden brown.

Allow the mixture to cool completely before cutting into it and definitely before topping it with powdered sugar (optional). Remember, if you put powdered sugar on top of warm lemon bars, the lemon bars will absorb the sugar, and they won’t look as pretty.

Sprinkle the powdered sugar on top only when the lemon bars are fully cool and just before serving.

To speed up the cooling process, allow the lemon bars to come to room temperature for about 30-60 minutes, then cover them with aluminum foil or plastic wrap before placing them in the fridge. The cold air from the refrigerator will help the custard filling to firm up and set. Leaving them in the fridge overnight nets the best results, ensuring they cut more beautifully.

Another strategy for cutting the lemon bars so they look clean is to use a sharp knife that you run under hot water for 10 seconds. Dry the knife, then cut into the cold lemon bars. You’ll get a clean cut every time. Clean and reheat your knife between cuts.

You can cut them into nine large squares or 16 small bite-sized squares. The ones pictured are cut into large squares.

Tip! Trim off the edges to ensure the lemon bars are evenly shaped and pretty when cutting them. You can eat the edges as a reward for your hard work.

Leftover lemon bars should be stored in an airtight container in the fridge. They will last for 5-6 days in the refrigerator. You can also freeze them for more extended storage. Do not add the powdered sugar until just before serving.

Why I Love These Lemon Bars

These gluten-free lemon bars have a lot going for them, and they, indeed, are one of my favorite non-chocolate desserts.

Flaky and Buttery Crust: These lemon bars boast a flaky and buttery crust that melts in your mouth. The crust holds together just enough to keep the lemon bars stable but falls apart once you put them in your mouth. Perfection!

Ultra-Lemon Flavor: One of the best parts of these lemon bars is the creamy lemon bar filling, which boasts a vibrant lemon flavor. You can taste the fresh-squeezed lemon and lemon zest. Some lemon bars use artificial lemon extract, but these lemon bars are flavored with natural lemon flavors.

Smooth Custard Filling: The lemon bars’ filling offers a smooth and velvety texture that almost melts on your tongue. It’s slightly tart and slightly sweet, and the whole concoction works harmoniously together.

They’re Beautiful: These gluten-free lemon bars are bright and beautiful. The irresistible combination of a lemony custard filling atop a flaky shortbread crust makes me feel like I’m eating a little piece of sunshine.

I hope you enjoy this ultimate gluten-free lemon bar recipe, which is for lemon lovers only. I know it will delight your taste buds without compromising your gluten-free diet or health.

Enjoy them at a picnic, baby shower, wedding shower, potluck party, summer barbecue, holiday party, for Valentine’s Day, and more!

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