You’re going to love these 7-ingredient key lime pie bars, a square version of my favorite key lime pie recipe. Cream cheese adds the most delightful cheesecake flavor (and helps the bars set!), and a buttery graham cracker crust is a wonderful base for the tangy filling.
I originally posted this recipe in 2014 and have since added new photos, a video tutorial, and more helpful success tips.
One reader, Lisa, commented: “Loved, loved, loved these bars. Made them for Easter and EVERYONE said to keep this recipe. It was very easy and delicious. Creamy and tart. Very well balanced, especially when topped with homemade whipped cream. Definitely making these again… ★★★★★”
Like key lime pie (or even mini margarita cheesecakes!), these key lime pie bars are truly one of the most refreshing, flavorful spring/summer desserts. And you know what? They’re incredibly easy to make.
Today’s recipe is typically my go-to when I need a no-fuss crowd pleasing dessert. I just brought them to a BBQ the other night! (See even more BBQ cookout desserts.)
Why You’ll Love These Key Lime Pie Squares
- All the texture and flavor of traditional key lime pie, but a little more cheesecake-y
- Only 7 ingredients (see all of my 8 ingredients or fewer recipes)
- Tangy-sweet flavor
- Thick, buttery graham cracker crust, or spice things up with gingersnap crumbs!
- Grab & go—no fork needed!
You Need Just 7 Ingredients:
And this includes the crust. I count key lime zest AND juice as 1 ingredient… key limes!
Start With a Crumb Crust
Below you’ll find my basic graham cracker crust recipe. It fits into a 9-inch square baking pan perfectly, as well as many 8-inch and 10-inch pans, and pie dishes. I love this particular crust because it’s altogether crunchy, buttery, thick, and not overly sweet like many crumb crusts of its kind. I use it for strawberry cream cheese pie, lemon blueberry cheesecake bars, and these mini key lime pies.
- You need a careful ratio of 3 ingredients: graham cracker crumbs, sugar, & melted butter.
- Use a food processor or blender to grind 12 full-sheet graham crackers into crumbs.
- Stir the graham cracker crumbs and sugar together before mixing in the melted butter.
- Press into your lined pan just until it’s no longer crumbly. Do not pack down too hard.
Other crust options:
- Gingersnap Crust: The original version of this recipe called for a crust made from finely crushed gingersnap cookie crumbs mixed with melted salted butter. I used store-bought gingersnaps, the hard and crunchy kind. The sweet/spicy flavor of the gingersnaps is an unexpected and delightful contrast to the tangy flavor of key lime. If you’d like to make the crust with gingersnaps, you can find the instructions in the recipe Notes. (Gingersnap cookie crumbs would be unbelievable on these upside down key lime pies, too!)
- Graham Nut Crust: Or you could combine graham cracker crumbs with ground macadamia nuts, like I do in my favorite key lime pie recipe.
- Pretzel Crust: Or try the pretzel crust from these peanut butter cup pretzel bars.
No matter which crumb crust you choose to use, press it into a 9-inch square baking pan lined with parchment paper, and give it a head start in the oven while you mix together your filling. (10 minutes prebake, as instructed below.)
Key Lime Pie Square Filling
This 4-ingredient filling is tart, creamy, and sweet. The perfect balance of all three. Tangy, not sour. Smooth, with just the right custard-meets-cheesecake texture.
First, you need key lime juice.
Key limes can be difficult to track down out of season, which is the majority of the year. They’re smaller, more yellow, and a little sweeter than standard limes. You can substitute regular limes for key limes in this recipe, or use half lime juice and half lemon juice.
Yes, absolutely. The brand I typically buy is called Nellie & Joe’s Key West Lime Juice, and it’s sold in most major grocery stores next to the bottled lemon juice. Not only does this make it possible for year-round key lime pie squares, but it’s also a lot easier than juicing all those tiny key limes by hand!
You also need the following ingredients:
- Cream Cheese: I don’t use it in my key lime pie recipe, but I wanted today’s filling to lean a little more towards key lime cheesecake. The flavor is subtle—we’re only using 4 ounces of cream cheese in the filling (1/2 of a brick), and that small amount manages to produce the creamiest key lime pie bars in the world. Avoid the fat-free kind.
- Egg Yolks: Egg yolks stabilize and set up the key lime filling.
- Sweetened Condensed Milk: One 14-ounce can of full-fat sweetened condensed milk sweetens the dessert and provides a smooth texture. I also use this in my oatmeal lemon crumble bars.
- Lime Zest: Lime zest gives the filling some colorful speckles, not to mention even more lime flavor. Zest either 1 regular lime or 2 key limes.
Spread the filling over the crust while the crust is still warm. Why? This will help the filling adhere to the crust a little better.
The bars don’t take long to bake to bake, but they do require cooling and chilling before you can slice into them.
How to Cut Neat Squares
Cool baked key lime pie bars at room temperature for about 1 hour, and then refrigerate them for 2 hours or until the bottom of the pan feels cold. If you cut the bars into squares too early, they’ll fall apart. If I’m serving these at a party or event, I prepare them the night before just so I know they’ll cool and chill long enough to yield neat squares.
Slice them with a sharp knife and wipe the knife clean between each cut.
Are you hungry yet? Because I don’t have any key lime pie squares left to share. 😉
For more summer dessert inspiration, see my roundups of favorite Memorial Day recipes, 4th of July Desserts, and BBQ cookout dessert recipes.
More Key Lime Recipes
Key Lime Pie Bars
- Prep Time: 15 minutes
- Cook Time: 30 minutes
- Total Time: 3 hours, 30 minutes
- Yield: 16 bars
- Category: Bars
- Method: Baking
- Cuisine: American
Description
You need just 7 ingredients to make these simple key lime pie bars, a handheld version of my key lime pie recipe. Today’s bars are creamy and tangy with a simple graham cracker crust. Be sure to cool and chill the bars before cutting into squares.
Ingredients
Crust
- 12 full-sheet graham crackers (to yield 1 and 1/2 cups (180g) graham cracker crumbs)
- 6 Tablespoons (85g) unsalted butter, melted
- 1/4 cup (50g) granulated sugar
Filling
- 4 ounces (113g) full-fat brick cream cheese, softened to room temperature
- 4 large egg yolks
- 14-ounce (397g) can of sweetened condensed milk
- 1/2 cup (120ml) key lime juice
- 2 teaspoons lime zest (about 1 lime or 2 key limes)
- optional for garnish: whipped cream and lime slices
Instructions
- Preheat oven to 350°F (177°C). Line a 9-inch square baking pan (I love this one and this one) with parchment paper, leaving an overhang on the sides to easily lift the bars out of the pan. Set aside.
- Make the crust: If you’re starting out with full graham crackers, use a food processor or blender to grind them into fine crumbs. You can also place them in a zip-top bag and crush them into fine crumbs with a little arm muscle and a rolling pin. Stir the graham cracker crumbs and granulated sugar together in a medium bowl, and then stir in the melted butter. The mixture will be thick, coarse, and sandy. Try to smash/break up any large chunks. Press into the bottom of the lined pan.
- Prebake crust: Bake the crust for 10 minutes. Cool for a few minutes as you prepare the filling in the next step.
- Make the filling: Using a handheld or stand mixer fitted with a paddle or whisk attachment, beat the cream cheese on medium-high speed until smooth, about 1 minute. Beat in the egg yolks. Scrape down the sides of the bowl as needed. Beat in the sweetened condensed milk, key lime juice, and lime zest until combined. After mixing the filling with your mixer, give it a final whisk by hand to make sure there are no cream cheese lumps at the bottom of the bowl. Pour/spoon filling evenly onto the warm crust.
- Bake for about 18-20 minutes, or until the edges of the bars appear set and the center is only *slightly* jiggly.
- Remove from the oven and allow to cool for 30 minutes at room temperature on a wire rack and then chill in the refrigerator for at least 2-3 hours.
- Lift the parchment paper out of the pan and cut into squares. Feel free to garnish with whipped cream, lime slices, and/or extra lime zest. I used Wilton 1M piping tip on the pictured bars.
- The bars stay fresh in an airtight container in the refrigerator for up to 5 days.
Notes
- Make Ahead & Freezing Instructions: You can freeze the bars for up to 3 months. Thaw overnight in the refrigerator before serving.
- Special Tools (affiliate links): Food Processor | 9-inch Square Baking Pan (like this one or this this one) | Glass Mixing Bowl | Citrus Zester | Citrus Juicer | Electric Mixer (Handheld or Stand) | Cooling Rack | Piping Bag (Reusable or Disposable) | Wilton 1M Piping Tip
- Non-US Readers: Don’t have graham crackers where you live? Use 200g ground digestive biscuit crumbs instead (about 13–14 biscuits), the same amount of butter, and add a bit more sugar (about 1/3 cup, or 67g). You may need to add a few extra minutes to the pre-baking time, as digestive biscuits are not quite as crispy-crunchy as graham crackers. And from what I understand, spreadable cream cheese sold in a tub in countries outside of the US is a little different from the spreadable cream cheese in the US. It’s thicker, sturdier, and more solid and should be OK to make cheesecake. I have no experience with it, but this is what I’ve heard from other non-US readers.
- Gingersnap Crust: The original recipe used to call for a gingersnap crust. To make this version, combine 2 cups (240g) finely crushed crunchy gingersnap cookies with 3 Tablespoons melted salted butter. Pre-baking and baking instructions remain the same.
- Can I Bake This in a 9×13-inch Pan? You can, but I have had better results baking a smaller batch, as written, in the 9-inch pan. If you want to make a larger batch, double each ingredient and bake in a 9×13-inch pan. Prebake the crust for 10 minutes, pour in the filling, and bake for about 35 minutes.
- Leftover Egg Whites: Here are all my recipes that call for egg whites.
I made this for a church gathering, so I needed to scale it up. I tripled the recipe and used a half sheet pan. I pre cooked the pie filling on the stove till it was hot but not hot enough to set up, maybe 140-150 degrees (not sure didn’t measure);and then put in in the oven on a still warm crust. In 20 minutes at 300 it hit 170 in the center and only had tiny cracks on the edges that disappeared when it settled.
I added green food coloring to the mix and put home made whipped cream and lime slices like in the pictures, 24 dollops for 24 slices. It was such a huge hit, I didn’t even get a piece! Willaoe again!
Love the fact that despite only using half a brick of cream cheese it tasted amazing. Made them yesterday, and this afternoon a dream to cut.
As a side note I use Lotus ‘ Biscoff’ cookies grind them up and use as a base for the squares( use the entire box if you want a really nice base).
Many thanks for sharing.
Anne
These are excellent. I did a shortbread crust (butter, sugar, flour) instead of the graham crust. The filling, I made per the instructions except added some vanilla paste and extract. I topped them with Sally’s marshmallow fluff frosting and some lime zest. So good! Definitely will be making these again!
Hi, making the gingersnap version of this. If I’m reading this correctly, the gingersnap crust is just the ginger cookies and butter? Or are those ingredients in addition to the sugar and salt with the regular crust?
Thanks in advance.
Hi Jenn, store-bought gingersnap cookies contain more sugar, so you do not need additional sugar to help bind and sweeten the crumb crust.
Can you bake in 2 9-inch square pans? If so, how long to bake? Thanks!
Hi Sean, the recipe is written for a 9-inch square pan. You would need to make two batches for two 9-inch square pans. Hope you enjoy the bars if you give them a try!
Has anyone tried making these bars in a pre made graham cracker pie crust (6oz size)?
Hi Jenna, you could try our mini key lime pies recipe instead. Fill your pre-made crust pan and then use any leftover batter for a few mini pies on the side. Enjoy!
Can I use gluten free graham crackers in this recipe to make the bars gluten free?
Hi Ann, that should work well!
Has anyone tried this using limeade concentrate instead of lime juice
Hi Miss Judy, we don’t recommend it. Lime juice concentrate often has several other ingredients in it, and the bars would likely be too sweet.
10/10 if you’re reading this, just make it. It’s amazing!!
I need to serve a crowd of 20 people. How can I increase this and what size baking dish? Thank you.
Hi Denise, see recipe notes for details on baking in a 9×13-inch pan. Enjoy!
So good! Everyone loved them. Could these be made using cupcake liners?
Hi Juliana, Glad you enjoyed them! You can follow recipe for mini key lime pies if you wish to use cupcake liners.
I made these bars for the 4th of July. They were delicious, but seemed to be a bit “shorter” than your photos. I truly believed I followed the recipe accurately and used the correct size pan. Can you check the recipe? Are you sure it shouldn’t be 8 oz of cream cheese rather than 4 oz? I made them look less wimpy with lots of whipped cream! (Or maybe your photo used a 8×8 pan rather than the 9×9 suggested.) Thank you!
Hi Deb! I used a 9-inch pan for the pictured bars. I’ve noticed that a lot of square baking pans that are labeled as 9-inch can really be 9.5 inches or even 8.5 inches and this will affect the thickness/height of the finished bars. You do not need 8 ounces of cream cheese in this recipe, though I’m sure it wouldn’t hurt if you added it. The bars will taste more like cheesecake.
In the key limes bar recipe, how many small limes will I need between the juice and zest? Btw, my family lives in Monkton, MD…and I see u r a Marylander, too!
Hi Debbie! Limes vary by size and your definition of a small lime may be different than ours, which is why we give the cup and weight measurements. You can also use bottled key lime juice (see post above for details). Happy baking!
Hi there! Do these key lime bars need to be refrigerated at all times?
Hi Joanna! The bars are best stored and served chilled.
This was a simple but delicious summer dessert
Made for dinner with some friends and we all fell in love with how delicious this recipe is. Had a couple leftovers to have my inlaws try it and now my FIL keeps calling me to see if I can make him some more. Definitely going into my roster of desserts for family get togethers 😀
I made these yesterday.
In Canada the Sweetened Condensed Milk is in a smaller amount 300ml instead of 390 ml so I just reduced the amount of Lime Juice by 2Tbsp.
They turned out perfectly and taste wonderful.
Thanks for another great recipe!
Hi. Can I use full fat spreadable cream cheese?
Hi Nanci, spreadable cream cheese has more water content that block cream cheese, and would lead to bars that don’t set up properly.
This was a wonderful treat! I doubled everything and baked in a jelly roll pan (15×10 and one inch sides) It fit perfectly and served a crowd. Just a delightful light summer dessert. Everyone loved it!
Hi Lynn! This is the pan size I need to make in a couple of days. What where your baking times when doing the 15×10 jelly roll pan? Please and thank you!
Hi Sally! This recipe sounds so delicious and refreshing! If I were to half the recipe, which pan size should I use? And would it work fine just halving all ingredients? Thanks a lot in advance!
Hi Marta, we haven’t tried halving this recipe and using a smaller pan. For best results, we’d recommend making as-is and freezing any leftovers!
do you have recipe for a 9×13 pan… Do I just double the recipe .
thanks
Hi Melissa, see recipe notes for 9×13 details: “You can, but I have had better results baking a smaller batch, as written, in the 9-inch pan. If you want to make a larger batch, double each ingredient and bake in a 9×13-inch pan. Prebake the crust for 10 minutes, pour in the filling, and bake for about 35 minutes.”
While incredibly tasty, these came out less cheesecake-y than I expected and more like lemon bars. Still delicious!
I made the recipe exactly as written. It was easy and turned out so amazing. My family all loved it and I have already shared the recipe. I love key lime pie and these bars are almost almost better!
Hi! I am looking at making this for July 4th as it sounds heavenly! How do you think sweetened condensed Coconut milk would work for this recipe?
Hi Hannah, we haven’t tested these bars with sweetened condensed coconut milk, but please do let us know if you try it!
Hannah, did you try this with sweetened condensed coconut milk? Dairy-free me would love to know!