Making Lemon Lime Bars with a buttery shortbread crust is a breeze! They’re a cross between classic lemon bars and key lime pie—creamy perfection!
These sweet-tart bars are perfect for an afternoon picnic, baby showers, a springtime tea, or just because you want an amazing sweet-tart buttery bar.
Raise your hand if you love lemon bars? I do — you need to try this old-fashioned lemon square recipe. I wanted to marry this best key lime pie and lemon squares — it’s a match made in heaven!
I enjoy giving precise details in my recipe posts to lead my readers through any questions. If you’re just here for the printable recipe, use the Jump to Recipe to head straight there!
Simple Ingredients for Lemon Lime Squares
- Shortbread Crust – Make the crust with flour, powdered sugar for sweetness, kosher salt, and melted butter. I use unbleached all-purpose flour and salted butter. If using unsalted butter, increase the salt to ½ teaspoon.
- Sugar – Add granulated sugar to sweeten the lemon-lime filling and cut the tartness.
- Zest – Freshly grate lemon zest from about two lemons and lime zest from about two limes. I also like to have a little extra as a garnish.
- Lemons – Squeeze fresh lemon juice from about 3-4 lemons; you can also use Meyer lemons!
- Limes – Use fresh lime juice for the best citrus flavor. I used Persian limes, but you could easily use key limes.
- Eggs – Eggs will bring all of the ingredients together, giving you that beautiful silky custard liking filling.
- Whipped cream— Combine heavy whipping cream, powdered sugar, and vanilla extract to make a fluffy and simple topping. If preferred, use granulated sugar instead of powdered.
Get the full recipe in the recipe card below.
How to Make Lemon Lime Squares
Step 1 | Preheat and prep
Start by preheating the oven to 350° F (175° C) and line a 9×13-inch baking pan with parchment paper or aluminum foil sprayed with cooking spray. Then, set it aside for later.
Step 2 | Combine dough ingredients
Add flour, powdered sugar, and salt to a medium bowl and mix well. Then, add the melted butter and use an electric mixer with paddles or a wooden spoon. Your hands will also do the trick!
Press the dough firmly into the bottom of the prepared pan using the bottom of a measuring cup. Bake the shortbread crust for about 20 minutes or until it’s a light golden brown around the edges.
Step 3 | Make the lemon-lime filling
Next, make the lemon-lime filling by adding sugar, lemon zest, and lime zest to a food processor or mixer. Blend until the zest and sugar are well combined. Then, add the rest of the flour and blend the ingredients. Add the lemon juice, lime juice, and eggs, mixing until fully incorporated.
Step 4 | Bake the bars
After the hot crust has cooled a bit, pour the filling over it in an even layer and return the pan to the oven to bake for 30 to 40 minutes. After the first 15 minutes, turn the pan for even baking. Check if the lemon-lime bars are baking by wiggling the pan. If it jiggles, bake for a little longer. But if it doesn’t, it’s ready to remove and cool!
Step 5 | Cool and chill
Allow the bars to cool on a wire rack in the dish for about an hour before moving to the fridge to chill for at least 2 hours.
Step 6 | Mix the whipped topping
To make the creamy whipped topping, add chilled cream and sugar to a large bowl and beat on medium-high for about 2 minutes or until thick. Scoop the topping onto the cooled lemon lime bars, spreading with a spatula.
Lastly, garnish the sweet, tart bars with a bit of fresh zest and lemon and lime wedges.
Fresh Tips
- Be careful not to overbake the bars. Check them early to ensure they cook for the right amount of time to achieve the perfect texture.
- Prep Ingredients – Remove the eggs from the fridge to come to room temperature for best results.
If you love this lemon-lime bar recipe’s ease and refreshing zesty taste, you’ll also enjoy my Lemon Cranberry Bars and these classic Old Fashioned Lemon Squares – they are both delicious!
Variations
Lemon-Lime Bars with Graham Cracker Crust
For a sweet graham cracker crust, crush graham crackers into about 2 ½ cups of crumbs using a food processor or a baggie and a rolling pin. Then, add ¼ cup of brown sugar or granulated sugar and 8 to 10 tablespoons of melted butter. Pack them all together into the baking dish, using the bottom of a measuring cup to flatten evenly. Bake for 10 minutes at 350°F.
Lemon-Lime Bars with Ritz Cracker Crust
You can also use buttery Ritz crackers for the crust. Crush 4 sleeves of crackers, add 8 tablespoons of cold salted butter cut into small cubes, and 6-7 tablespoons of brown sugar. Mix well and evenly press the cracker mixture into the baking dish, then bake at 350°F for 12 to 15 minutes or until golden.
Gluten-Free Lemon Lime Bars
To make these bars gluten-free, replace the flour in the crust with a mix of half gluten-free all-purpose flour and half almond flour. Replace the flour in the bar filling with something like Bob’s Red Mill Gluten-Free 1-1 Baking Flour.
Dairy-Free Lemon Lime Bars
Lemon lime bars can easily be made dairy-free by replacing the butter with a plant-based alternative, omitting the whipping cream, or swapping it with your favorite non-dairy whipped topping.
Substitutions
- Instead of making homemade whipped cream, substitute with thawed whipped topping from the grocery store, like Cool-Whip.
- Granulated sugar can be swapped with alternatives like coconut or brown sugar for a slightly different flavor profile.
- Butter can be replaced with margarine or a dairy-free butter substitute for a vegan version. You can also use oil, like vegetable oil or coconut oil.
- Omit the whipped cream topping and instead dust with powdered sugar, also called confectioners sugar.
Frequently Asked Questions
If you notice a thin ‘crust’ on top of the lemon-lime bars, this is normal! It happens when the sugar caramelizes during baking and is actually my favorite part!
First, make sure they are completely cooled and chilled well! Lift the bars out of the pan using the parchment paper. You want a thin, sharp knife to delicately and neatly slice the lemon bars without smashing them.
They are likely underbaked. Make sure that you bake them until the edges pull away from the side and the center no longer jiggles. Be sure to cool them well, that will help them firm up too.
Yes! This is an excellent way to save lemons and limes before they go bad. Wash and dry them, then keep them in an airtight bag in the freezer for up to three months. Let them thaw completely before using them for this recipe.
You bet! Use the tool on the recipe card below and reduce the servings to half, bake in an 8×8 or 9×9 inch square pan as directed!
Storage Tips
Refrigerate – Store leftover bars or make this recipe in advance by placing the cooled bars in an airtight container in the refrigerator for up to a week.
Freezer-Friendly Instructions: Completey cool the bars before freezing. Cover the whole batch tightly with aluminum foil or plastic wrap (I usually do both). Freeze up to 3 months. Thaw overnight in the fridge, then cut the bars into squares. If desired, omit the whipping cream topping and instead sprinkl with powdered sugar before serving.
What to serve with Zesty Lemon Lime Bars
More delicious Dessert Bar Recipes
- Oatmeal Cranberry Bars
- Frosted Sugar Cookie Bars
- Buckeye Bars Recipe
- Chewy Blondie Bars Recipe
- Snickers Candy Bar Fudge
Be sure to bring your eggs to room temperature first and cool the bars completely before cutting.
I hope you loved these Lemon Lime Bars. — if you did, would you share your creation on Instagram, Facebook and Pinterest? Comment and rate below!
Like this recipe?
Don’t forget to give it a ⭐️⭐️⭐️⭐️⭐️ star rating and leave a comment below the recipe!
Ingredients
Shortbread Crust
- 2 ½ cups unbleached all-purpose Flour regular flour may be used, see notes for gluten-free
- ½ cups powdered sugar also called confectioners sugar
- ¼ teaspoon kosher salt
- 12 tablespoons butter ¾ cup=1 ½ sticks melted (if using unsalted butter, increase salt to ½ tsp)
Lemon-Lime Filling
- 2 ½ – 3 cups granulated sugar Based on sweet-sour ratio desired
- 2 tablespoons Lemon Zest apx 2 Lemons, plus 1 teaspoon to garnish
- 2 tablespoons Lime Zest apx 2 Limes, plus 1 teaspoon to garnish
- ½ cup all purpose flour
- ½ cup Lemon Juice fresh squeezed, about 3-4 lemons
- ½ cup Lime Juice fresh squeezed, about 3-4 limes
- 8 large Eggs room temperature
Whipped Cream Topping
- 1 ½ cups heavy whipping cream chilled!
- 2 tablespoons powdered sugar or granuulated sugar
- ½ teaspoon vanilla extract
Instructions
Shortbread Crust
- Preheat oven to 350° F (175° C). Line a 9×13-inch baking pan with parchment paper or foil sprayed with cooking spray. Set aside.
- In a medium bowl sift together 2 ½ cups flour, Confectioners’ Sugar, and Salt.Add melted butter and blend until combined. This is easier with an electric mixer, with paddles attachment.2 ½ cups unbleached all-purpose Flour, ½ cups powdered sugar, ¼ teaspoon kosher salt, 12 tablespoons butter
- Add the dough into the lined pan and press into a flat thin layer with the bottom of a measuring cup. Bake for about 20 minutes, until a light golden color around the edges. Cool 15-30 minutes before adding lemon-lime filling.
Lemon-Lime Filling
- Place sugar in a food processor or mixer, and add the Lemon Zest and Lime Zest. Pulse or blend until the Zest is fully incorporated and the Sugar is a light green color.2 ½ – 3 cups granulated sugar, 2 tablespoons Lemon Zest, 2 tablespoons Lime Zest
- Add the remaining half cup of flour to the sugar mixture and blend well. Add Lemon Juice, Lime Juice, and Eggs, and blend until completely combined.½ cup all purpose flour, ½ cup Lemon Juice, ½ cup Lime Juice, 8 large Eggs
- Pour the filling over the crust and place it in the oven. Bake for 30-40 minutes, turning the pan after 15 minutes. Check for doneness by wiggling the pan. If it doesn’t jiggle in the middle, it’s done.Do not overbake. Remove from oven and allow to cool for an hour before chilling in the fridge for at least two hours.
Whipped Cream Topping (Optional)
- Pour chilled cream and sugar into a mixing bowl. Beat on medium-high speed for approximately 2 minutes until thick and spreadable.
- Spoon onto the Lemon-Lime Filling layer and spread evenly with an offset spatula. Garnish with reserved Zest, and Lemon and Lime wedges as desired. Refrigerate longer for better cutting, use a sharp thin knife once completely chilled to cut into squares.
Notes
- May substitute the whipping cream with thawed whipped topping if desired, such as Cool Whip.
- Make a graham cracker crust using 2 ½ cups Graham cracker crumbs (about 2 sleeves of graham crackers processed into fine crumbs), ¼ cup brown sugar packed light or dark and 8-10 tablespoons butter, melted. Mix together and pack into 9×13 baking dish, compacting with the bottom of a measuring cup. Bake at 350°F for 10 minutes.
- Make a Ritz Cracker Crust: Crush 4 sleeves of Ritz Crackers in a food processor until coarse crumbs. Add 8 tablespoons salted butter, very cold cut into ½ inch cubes, and 6-7 tablespoons brown sugar and pulse until butter starts to hold it all together. Press into a 9×13 inch prepared baking dish and bake 350° F (175° C) for 12-15 minutes until golden brown.
- Gluten-Free Lemon Lime Bars: These bars are so easy to make gluten-free! Replace the flour in the shortbread crust with ½ good cups for cup gluten-free all-purpose flour and ½ almond flour (or use all GF AP Flour). Replace the flour in the lemon lime bars with binder (such as Bob’s Red Mill Gluten-Free 1-1 Baking Flour).
- Dairy Free Lemon Lime Bars:Also an easy swap, replace the butter with your favorite plant-based stick butter and follow the instructions. Omit the whipping cream or replace with your favorite Non-Dairy whipped topping.
- High Altitude Lemon Lime Bars: This recipe does not need any adjustments for high-altitude and was tested at sea level and at high altitude (5280 feet above sea level).
Nutrition
Susan Brandenburg
I would love to be a tester from Charlotte, NC! I love your recipes, the directions are detailed and easy to follow.
Thanks so much Susan! I will reach out to you!