Key Lime Pie Bars are a little sweet, very tart, and smooth and creamy over a crumbly golden (homemade) graham cracker crust. Can you believe these take only minutes to prep and bake?
Key Lime Pie is one of those desserts that was always under-appreciated in my household growing up, and I just don’t understand why.
Well that’s not exactly fair to say. My Dad has always liked and asked for key lime pie, but his requests fell on deaf ears to a family whose default desserts were almost exclusively chocolate chip cookies and brownies. We had plenty of apple pies, but never key lime, which is interesting to me considering how much easier the latter is to make.
For Father’s Day, I made my dad a Key Lime Pie again this year, and because it was so easy, I started experimenting with turning the pie into dessert bars.
It was honestly very simple to develop a winning key lime pie bar recipe.
I used my simple, favorite graham cracker crust recipe for the crust, which fit nicely into a 9″ square pan. The key lime filling is only four ingredients, you literally whisk together sweetened condensed milk, key lime juice, lime zest, and sour cream
Total bake time is less than ten minutes for the crust and then less than ten minutes again for the filling.
Keep in mind that this recipe calls for key limes, which are different from regular limes in both flavor and size. Key limes are about the size of ping-pong balls, and juicing them can take quite a long time. Using a bottled key lime juice is acceptable, but usually I prefer to use at least a combination of fresh-squeezed and bottled.
Here’s a hand-saving tip if you decide to use fresh-squeezed: Use a garlic press.
Halve your key limes, place them in the press (rind-side up) and then squeeze the juices into a measuring cup. I’ll usually still run everything through a mesh sieve to catch any pulp or tiny seeds that escape through, but the press does a good job at minimizing that, too.
Even though these are bars, which are usually very grab-and-go-friendly, I recommend using a fork to eat them, as I found them to be a little bit too heavy to eat by hand. That may have also had something to do with the fact that I cut the whole pan into just 9 gigantic squares… but who knows.
Enjoy!

Key Lime Bars
Ingredients
Graham Cracker Crust
- 1 1/2 cups graham cracker crumbs 170g
- 2 Tablespoons sugar
- 1 Tablespoon brown sugar tightly packed
- 6 Tablespoons butter melted, 85g
Key Lime Pie Bar Filling
- 2 14 oz cans sweetened condensed milk 795g
- 2/3 cup key lime juice 150ml
- 1/3 cup sour cream 75g
- 2 teaspoons lime zest
Instructions
Graham Cracker Crust
- Preheat oven to 350F and line a 9x9 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 for 7 minutes. Allow to cool slightly while you prepare your key lime filling.
Key Lime Filling
- In a large bowl, whisk together sweetened condensed milk, key lime juice, sour cream, and lemon zest until mixture is smooth.
- Pour into prepared pie crust and bake for 8-10 minutes, until mixture is set.
- 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.
Nutrition
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Dee Kirkland says
These are wonderful and I’ve already made them twice, def worthy of a recipe card! Thanks so much!!❤️
Sam says
I am so glad you enjoyed them so much, Dee! 🙂
Michelle says
Hi Sam!
Is there anything else I could use for the crust? I just realized I’m out of graham crackers.
Thanks!
Sam says
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 says
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 says
Thank you so much, Chantal! I think you’ll love the finished product just as much. 🙂
Hannah says
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 says
Hi Hannah! That should be just fine. Make sure to wrap them so they don’t dry out. 🙂
Melanie says
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 says
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 says
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 says
LIME! Don’t know where my brain was when I typed lemon. I’ll fix that. Enjoy the bars, Claire!
Kelsey says
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 says
I’m so glad you enjoyed them, Kelsey!
Sheenam says
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 says
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 says
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 says
Key lime pie is my absolute faaave summer treat! These look too good… gotta try them soon!
Sues says
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 says
Thank you, Sues!:)