Key Lime Pie Bars are a little sweet, very tart, and smooth and creamy over a crumbly golden (homemade) graham cracker crust. They’re also incidentally egg-free! Can you believe these take only minutes to prep and bake? Recipe includes a how-to video!
Rich, creamy, and only slightly sweetened, these key lime pie bars are perfectly tart, enough to make your mouth pucker just thinking about them. Fans of my lemon bars will love these tart treats (and perhaps even more they’ll love how easy these bars are to make in comparison).
Served on a crumbly, perfectly sweetened graham cracker crust, today’s recipe is obviously inspired by my key lime pie, but look closely at the ingredients (which I highlight below) and you’ll see that there are some noteworthy differences.
What You Need
- Sweetened Condensed Milk. This is the base of our pie filling and serves as our sweetener. Do not substitute evaporated milk (this seems to be a common mistake, please note they are not the same thing and your bars will not only taste right but they won’t set properly if you use evaporated milk).
- Sour cream. To make this recipe easy (and, incidentally, egg free), I ultimately ended up swapping out the the 6 egg yolks that I used in my pie recipe with sour cream (I can’t help wanting to change things up from recipe to recipe!). The results are rich and creamy and a bit more tart/sour than my classic pie, but every bit as good!
- Key limes. Key limes are tiny (ping-pong-ball-sized) limes that may be either green or yellow (or a spotty combo of the two colors) that have a flavor that’s distinct from their more common grocery store counterparts (which are typically Persian limes). While I recommend using fresh key limes if you can find them, unfortunately I have always had a lot of trouble finding these in any grocery stores within 20 miles of me. If you can’t find key limes, don’t use “regular” limes, instead find yourself a bottle of key lime juice! Nellie & Joe’s brand is what I use, it’s typically sold near the lemon juice and I included a photo above.
SAM’S TIP: Here’s a hand-saving tip if you’re able to find fresh key limes: Use a garlic press!. Halve your limes, place them in the press (rind-side up) and then squeeze the juices into a measuring cup. So much easier than hand-squeezing!
Then of course you’ll also need graham cracker crumbs, sugar, and butter to make your graham cracker crust. Salted or unsalted butter will work equally well in the crust. I like to use a Tablespoon of brown sugar to help enhance the flavor of the crust, but if you don’t have any you can use all granulated sugar.
While it’s not strictly necessary, I highly recommend topping your bars with dollops of homemade whipped cream before serving. It adds a light, sweet, contrast to the otherwise tart bars!
How to Make Key Lime Pie Bars
- Prepare the graham cracker crust! Stir together graham cracker crumbs, sugar, and melted butter. Stir until all of the crumbs are coated with butter and the mixture is sandy and well-combined.
- Press crumbs into the bottom and part-way up the sides of a foil-lined 9×9″ baking pan. Press the bottom into an even layer, I like to use the back of a spoon or the clean, flat bottom of a measuring cup to do this.
- Whisk together the remaining ingredients (I actually recommend whisking together all of the ingredients except for the key lime juice, then whisking that in last as it’s much thinner than the other ingredients and adding it with the other ingredients can make it harder to incorporate) until the mixture is smooth.
- Pour key lime pie bar batter into prepared pan and use a spatula to spread the filling so you have a smooth layer.
SAM’S TIP: Lining the pan with foil isn’t absolutely necessary, but it does make it much easier to remove the key lime pie bars from the pan after baking. Make sure you use a long enough piece of foil that it hangs over two of the sides of the pan (creating a sort of sling). After baking and completely cooling the bars, use the excess foil to carefully lift them out of the pan, then easily cut and serve on your counter.
Frequently Asked Questions
I do not recommend it, as most limes available in the grocery store are Persian limes, which have a distinctly different flavor. If you can’t find key limes, purchase key lime juice instead, which can often be found near the lemon juice.
No! Green key lime pie is usually that color due to added food coloring. Key lime pie should be a creamy white/yellow color.
I don’t see why not! If you have excess batter, simply discard it, do not overflow your pie plate. I also should note that I already have a killer key lime pie recipe on the blog and prefer that when making a pie.
Enjoy!
Let’s bake together! I’ll be walking you through all the steps in my written recipe and video below! If you try this recipe, be sure to tag me on Instagram, and you can also find me on YouTube and Facebook
Key Lime Bars
Ingredients
Graham Cracker Crust
- 1 ½ cups graham cracker crumbs (170g)
- 2 Tablespoons sugar
- 1 Tablespoon brown sugar firmly packed
- 6 Tablespoons butter melted, (85g)
Key Lime Pie Bar Filling
- 2 14 oz cans sweetened condensed milk (795g)
- ⅓ cup sour cream (75g)
- 2 teaspoons lime zest optional
- ⅔ cup key lime juice (150ml)
- homemade whipped cream for topping, optional. Click the link for the recipe, you will only need ½ batch.
Recommended Equipment
- 9×9 baking pan
Instructions
Graham Cracker Crust
- Preheat oven to 350F (175C) and line a 9×9" (23x23cm) baking pan with foil. Set aside.
- Combine graham cracker crumbs, sugar, and brown sugar in a large bowl.
- Add melted butter and stir well.
- Press evenly and firmly into the bottom and up the sides of prepared pan.
- Bake on 350F (175C) for 7-8 minutes. Allow to cool slightly while you prepare your key lime filling.
Key Lime Filling
- In a large bowl, whisk together sweetened condensed milk, sour cream, and lime zest (if using) until mixture is smooth.
- Gradually whisk in key lime juice until mixture is smooth.
- Pour into prepared pie crust and bake for 8-10 minutes, until mixture is set if you jiggle the pan.
- Remove from oven and allow to cool to room temperature, then transfer to refrigerator and allow to chill 4-6 hours before cutting.
- Top with whipped cream, if desired, and serve.
Notes
Storing
Keep refrigerated in an airtight container for up to one week.Nutrition
Related Recipes
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This recipe was originally published June of 2017. The recipe remains the same, but I have updated the text to be more informative and have updated some of the photos and added a video.
Dimple
Sam, this is so delicious. I see that you can keep them in an airtight container for a week but can they be frozen at all?
I love all of your recipes!
Sam
I’m so glad you enjoyed! While I have never frozen them myself I think they should freeze just fine and should probably keep for at least a month or longer. I hope that helps, and thank you for trying my recipes! 🙂
hynes jim
Hi Sam
Made these for a neighborhoood 4th of July get together. The hit of the party.
Sugar Spun Run for the win!!!
Jim Hynes
Sam
I’m so glad everyone enjoyed them, Jim! 🙂
Dee Kirkland
These are wonderful and I’ve already made them twice, def worthy of a recipe card! Thanks so much!!❤️
Sam
I am so glad you enjoyed them so much, Dee! 🙂
Michelle
Hi Sam!
Is there anything else I could use for the crust? I just realized I’m out of graham crackers.
Thanks!
Sam
Hi Michelle! This may be a stretch but you could use my oreo crust and substitute golden oreos. You could also try the shortbread base that I use in my millionaire shortbread bars. 🙂
Chantal
I just took it out of the oven, now it’s time to cool but already loving this recipe! The mixture tasted great and it’s sooooo easy! Thank you for sharing 😃
Sam
Thank you so much, Chantal! I think you’ll love the finished product just as much. 🙂
Hannah
Hi! I am planning on making these bars this weekend. Would it be okay if I chilled the bars in the refrigerator overnight? Thank you so much and I love your recipes!!
Sam
Hi Hannah! That should be just fine. Make sure to wrap them so they don’t dry out. 🙂
Melanie
This recipe sounds amazing! I always use coconut sweetened condensed milk, but do you know what I could use as a dairy free alternative to sour cream?
Sam
Hi Melanie! I’m sorry but I’m not sure what might be a good dairy free substitute. I did do some googling and found this possible substitute, if that is helpful.
Claire
Lemon zest as in instructions, or lime zest as in ingredients? Having all those key limes for the juice, it would be logical to use those.
Sam
LIME! Don’t know where my brain was when I typed lemon. I’ll fix that. Enjoy the bars, Claire!
Kelsey
Great recipe! Couldn’t find a 9×9 cooking pan so I used 8×8. Cooked and set for a little longer and they turned out perfect. I’d probably look harder for a 9×9 next time as they are pretty rich!
Sam
I’m so glad you enjoyed them, Kelsey!
Sheenam
Hi Samantha, I absolutely loved this recipe right when I saw it on Instagram and I cannot wait to try this; the recipe looks so easy. I am definitely trying this and will mention your website as well 🙂 Can you tell me if I can use regular lemon for this?
Phyllis ferrentino
I know sweetened condensed milk is referenced in this recipe – can another type of canned milk be used ? Possibly with the addition of sweetener?
Ty Phyllis
Sam
Hi Phyllis! What kind of milk did you have in mind? I know it wouldn’t work with evaporated milk and haven’t tried it with anything other than sweetened condensed.
Karly
Key lime pie is my absolute faaave summer treat! These look too good… gotta try them soon!
Sues
These photos basically have me out of my chair and ready to run to the grocery store to gather up all the ingredients. They look SO delicious. Pinning!
Sam
Thank you, Sues!:)