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A classic key lime bar with a buttery graham cracker crust and an easy filling made with condensed milk! These bars have a creamy texture and tangy filling. Only 6 ingredients to make these easy key lime bars.
So growing up I don’t remember ever having a Key Lime Pie Bar. Or Key Lime Pie for that matter. Not once. Am I alone? We had your typical desserts- apple pie being big on that list around the holidays. It wasn’t until I got older that I got to experience how truly magnificent key lime pie was.
Before moving to Boston, I lived in Buffalo, NY where I worked at a restaurant while finishing up my master’s. It was there that I had the most delicious key lime pie. I finally got up the courage one day to ask the chef about the recipe. To my shock, he said “it was the recipe on the back of the condensed milk can”. You have got to be kidding.
This upscale restaurant was relying on a recipe off the back of the can?! And you know what? It didn’t matter. That key lime pie was the perfect balance of tangy and sweet and surrounded by this thick layer of a buttery graham cracker crust. Sometimes delicious does not need to equal difficult!
Now as much as I love whipping up an entire key lime pie – there’s something about a dessert bar. I feel like no one can resist pie in bar form. These bars start with a simple graham cracker crust that I whip up in my food processor. And then the filling is made in just minutes while the crust is baking. These bars have a wonderful sweet-tart flavor that can’t be beat.
These bars are everything you love about a traditional key lime pie – only in bar form!
- One of my all time favorite desserts are these lemon bars! They are made in one bowl so clean up is a breeze!
- When it’s summertime, then it’s time grab some marshmallows and make these delicious, easy S’mores bars!
- Grab a loaf pan and make my super fudgy small batch brownies! Makes a small amount perfect for sharing.
Why You Will Love These Key Lime Bars
- Just 6 Ingredients – Yup that’s it. Only six ingredients is all you need.
- Ready In Less Than An Hour – In just about 45 minutes these are done start to finish. And really it’s only about 20 minutes of prep work on your end. How awesome is that?
- Simple To Make. The hardest part is sometimes figuring out how to get that food processor lid to attach so I can turn it on. Tell me I’m not alone here! But seriously, that’s the hardest part. Otherwise these couldn’t be simpler.
- Perfect summer dessert to bring to barbeques and backyard get togethers!
Note: The entire recipe, with ingredient quantities and recipe directions can be found at the bottom of the page. Scroll to the bottom or click “Jump To Recipe” button at the top of the post.
- Graham Crackers – I turn these into graham cracker crumbs using my food processor but you could also throw them in a plastic bag and crush them with a rolling pin.
- Sweetened Condensed Milk – This is the key ingredient to making key lime pie. Make sure you grab the right can, and not evaporated milk!
- Limes – You will need 1/2 cup of fresh key lime juice. If you can’t find fresh key limes you can use bottled key lime juice. I’ve also made these in a pinch with regular limes (aka Persian Limes) and they still turn out wonderful! For a more true key lime flavor, you can use 1/2 lemon juice and 1/2 regular lime juice if you can’t find key limes.
- Egg yolks – For help on separate your eggs cleanly, read how to separate eggs (6 ways!).
- Butter – I prefer using unsalted butter vs. salted butter but either will work. You could also swap the melted butter for coconut oil
- Sugar – You want to use granulated sugar, but brown sugar in the crust would be a good swap!
How To Make These Key Lime Bars
Preheat your oven to 350°F. Line a 9×9 baking pan with parchment paper and spray with a cooking spray. You can also use an 8×8 square pan. I like to make a parchment sling by cutting away the corners of the paper so there will be an overhang. This will make it easier to lift out the bars after they’re baked.
Make The Crust
First let’s start with the crust. Because the key lime pie would be nothing without the graham cracker crust. Am I right? Making a graham cracker crust is simple to make as long as you use your food processor.
You want to process the graham crackers until they are fine crumbs. If you don’t own a food processor you can place the crackers into a large freezer bag and smash the mwith a rolling pin. It’s a great way to get out any frustrations one might have. Call it baking therapy.
After that just add melted butter and sugar to sweeten it a little. The graham cracker mixture gets pressed into the bottom of your baking pan. I just purchased this Cuisinart 9×9 baking pan and I’m in love.
You need to bake the crust for 10 minutes before adding your filling.
Heather’s Baking Tip
You can use the bottom of a measuring cup or just get in there with the hands and press the crumbs into the pan.
Make The Key Lime Filling
For the limes, I used both the juice and the zest for a really big lime flavor.
Once you have whisked the filling together go ahead and pour it over the graham cracker crust and bake for an additional 15 minutes. That’s it.
- Use The Bottom Of The Measuring Cup. To press down the crumbs into the pan. It really does make fast work of it.
- Buy extra limes. I sometimes find that I never get as much as juice out of them that I want. There’s always ones that seems dried up after I cut into it. So buy 5 or 6 and you should be all set!
- Roll them around. The limes that is. I find this helps release the juices. You can also microwave your lime for 30 seconds as well to help it juice better.
- Use a sharp knife. To cut the bars that is. I like to cut with a sharp hot knife so it cuts through cleanly and then wipe off with a paper towel in between each cut so they cut neatly.
- Gluten Free: Use gluten free graham crackers in the crust.
- Dairy Free (Lactose Free): Use vegan butter or melted coconut oil in the crust. And swap for coconut sweetened condensed milk.
- Make it a bit healthier: You can use coconut sugar and coconut oil in the crust.
- Turn into lemon bars: Swap out the lime juice for lemon and make a fun twist on these bars.
- Add coconut or toasted nuts: You can add in 1/2 cup shredded coconut or toasted pecans to the crust for a crunchy twist!
- Swap the graham crackers. If you can’t find any, try using digestive biscuits, gingersnap cookies, or Nilla wafers instead.
Yes you can make these up to two days ahead of time. Just cover and store in the fridge in an airtight container. The crust may soften slightly, however.
You absolutely can if you want the true “key lime” flavor. I’ve never found it in my stores, so I buy it on Amazon. But I still recommend adding fresh lime zest if you can. Or you can swap and use 1/2 lemon juice and 1/2 regular lime juice. Or just use regular lime juice if you can’t find any!
Yes you can freeze these bars for up to 3 months. Wrap them well and then thaw in the fridge overnight before serving. You may find the crust softens slightly.
For More Bar Recipes Check Out These:
Let’s Bake Together!
Key Lime Bars
- 1 1/2 cups (12 graham crackers)
- 6 tablespoons (85 g) unsalted butter melted
- 1/4 cup (50g ) granulated sugar
- 4 large egg yolks
- 14- ounce can of sweetened condensed milk
- 1/2 cup (120 mL) lime juice (or use key lime juice)
- 2 teaspoons lime zest (about 1-2 limes)
- In a food processor, place your graham cracker sheets and pulse until finely ground. Empty the graham cracker crumbs into a mixing bowl, add in your melted butter and sugar. Stir to combine. Press the graham cracker crumb mixture into the 9×9 pan and press down into an even layer. Bake in the preheated oven for 10 minutes.
- In a second mixing bowl, combine the filling ingredients. Whisk to combine. Pour over the graham cracker crust and bake for an additional 15 minutes until set. Allow the bars to cool on a cooling rack before slicing. Bars can be refrigerated for up to 2 days, the crust may soften slightly however.
- Storage: Yes you can make these up to two days ahead of time. Just cover and store in the fridge. The crust may soften slightly, however.