If you’ve ever fallen in love with the tangy-sweet magic of a real Florida key lime pie, these Key Lime Pie Bars will steal your heart. I first made them on a humid summer afternoon, craving something bright and refreshing—and they’ve been a go-to ever since. With a buttery graham cracker crust and a creamy lime filling that hits the perfect balance of tart and sweet, these Key Lime Pie Bars are everything I love in a no-fuss dessert.
They come together quickly (under an hour, truly!) and don’t ask for any fancy tools—just simple ingredients and a bit of love. Whether you’re planning a backyard get-together or just want something cool from the fridge after dinner, these Key Lime Pie Bars deliver sunshine in every bite. And yes, regular lime juice works in a pinch, but if you spot key lime juice at the store—grab it!
Why Key Lime Pie Bars Are Perfect for Any Occasion
Key lime pie has been a Florida favorite since the 1800s, and it’s no surprise why—there’s just something magical about that bright citrusy tang against a creamy, sweet base. These Key Lime Pie Bars are my go-to way to bring that nostalgic flavor to parties, potlucks, or backyard dinners—without the fuss of slicing a full pie. I love how easily they pair with other summer treats like coconut macaroons or berry tarts, but they also shine during the holidays when you’re craving something a little lighter.
The tropical flavor makes Key Lime Pie Bars the perfect sweet ending after grilled meats or smoky BBQ. And if you’re cooking for a crowd, don’t worry—this recipe doubles beautifully in a bigger pan. Not only do these Key Lime Pie Bars taste like sunshine, but they also look so pretty on a dessert table with their soft green hue and buttery crust.
Jump to:
- Ingredients
- Instructions
- Dietary Benefits & Serving Suggestions
- Recipe Variations & Substitutions
- Equipment
- Storage
- The Secret I Learned the Hard Way For Perfect Key Lime Pie Bars (So You Don’t Have To)
- FAQ
- Why These Key Lime Pie Bars Deserve a Spot in Your Dessert Lineup
- Related
- Pairing
- Key Lime Pie Bars Recipe
Ingredients
For the Graham Cracker Crust:
- Graham cracker crumbs (about 12 whole crackers)
- Granulated sugar
- Unsalted butter, melted
- Pinch of salt
For the Key Lime Filling:
- Egg yolks
- Can sweetened condensed milk
- Fresh key lime juice (or regular lime juice)
- Lime zest (from about 4-5 limes)
- Vanilla extract
- Pinch of salt
For Garnish (Optional):
- Whipped cream
- Additional lime zest
- Lime slices
Substitution Notes: If key limes aren't available, regular Persian limes work perfectly and are actually easier to juice. For a gluten-free version, use gluten-free graham crackers. You can also substitute the graham crackers with vanilla wafers or even crushed gingersnaps for a different flavor twist.
See recipe card for quantities.
Instructions
Prepare and Make the Crust
- Preheat your oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, leaving some overhang for easy removal. This step is crucial – it makes getting clean bar cuts so much simpler later on. Lightly grease the parchment with cooking spray.
- In a medium bowl, combine graham cracker crumbs, sugar, and salt. Pour in the melted butter and mix until the mixture resembles wet sand and holds together when squeezed. Don't worry if it seems a bit dry at first – keep mixing and it will come together.
- Press this mixture firmly and evenly into the bottom of your prepared pan. Use the bottom of a measuring cup or your hands to really pack it down. The key to a good crust is making sure it's compact and even.
- Bake the crust for 10-12 minutes until it's lightly golden and set. This pre-baking step prevents a soggy bottom and gives you that perfect textural contrast between the crispy crust and creamy filling.
Create the Key Lime Filling
- While the crust bakes, whisk together the egg yolks in a medium bowl until smooth. Add the sweetened condensed milk and whisk until well combined. The mixture should be smooth and pale yellow.
- Add the fresh key lime juice, lime zest, vanilla, and salt. Whisk everything together until the filling is smooth and slightly thickened. The acid from the lime juice will start to thicken the mixture naturally – this is exactly what you want.
Assemble and Bake the Bars
- Pour the lime filling over the hot crust, spreading it evenly to the corners. The filling should cover the crust completely.
- Bake for 15-18 minutes, until the filling is set but still has a slight jiggle in the center when you gently shake the pan. Don't overbake – the filling will continue to set as it cools. You want these bars to be creamy, not rubbery.
Cool and Chill Your Key Lime Pie Bars
- Remove from the oven and let the bars cool completely at room temperature, about 1 hour.
- Refrigerate for at least 2 hours before cutting. This chilling time is essential for clean cuts and the proper texture.
- Step 1: Prepare and Make the Crust
Make and pre-bake the graham cracker crust.
- Step 2: Create the Key Lime Filling
Mix the creamy lime filling until smooth.
- Step 3: Assemble and Bake the Bars
Spread the lime filling over the crust and bake.
- Step 4: Cool and Chill Your Key Lime Pie Bars
Cool, chill thoroughly, and prepare to slice.
Hints and Tips for Successful Key Lime Pie Bars
Let the bars chill overnight for the absolute best texture and easiest cutting. The flavors also develop and meld beautifully with time. When you're ready to cut, use a sharp knife wiped clean between cuts for the prettiest presentation.
For extra tangy flavor, add an additional tablespoon of lime juice to the filling. Some people love that extra pucker! You can also try adding a drop of green food coloring if you want a more vibrant color, though it's completely optional.
Dietary Benefits & Serving Suggestions
These key lime bars provide vitamin C from the fresh lime juice and some protein from the eggs and condensed milk. While they're definitely a treat, they're portion-controlled and don't require any heavy cream or excessive butter like some desserts.
Serve these alongside fresh tropical fruit like pineapple or mango for a complete summer dessert spread. They also pair wonderfully with coconut ice cream or a simple dollop of whipped cream. For drinks, try them with iced tea, coffee, or even a light white wine for adult gatherings.
Recipe Variations & Substitutions
- Lemon Key Lime Pie Bars: Replace half the lime juice with fresh lemon juice for a more complex citrus flavor. This creates a beautiful balance that's slightly less tart than traditional key lime.
- No Bake Key Lime Pie Bars: Skip the baking step for the filling entirely. Instead, add 1 packet of unflavored gelatin dissolved in 2 tablespoons of warm water to the filling mixture. Chill for 4 hours until set.
- Coconut Key Lime Bars: Add ½ cup of sweetened shredded coconut to the crust mixture for a tropical twist. This pairs amazingly well with the lime flavor.
- Oreo Lime Dessert Bars: Replace the graham cracker crust with crushed Oreo cookies for a chocolate-lime combination that's absolutely divine.
For those following specific diets, you can make these bars dairy-free by using coconut condensed milk instead of regular sweetened condensed milk. The flavor actually complements the lime beautifully.
Equipment
A 9x13-inch metal baking pan works best for even baking and clean removal. Glass pans work too but may require a few extra minutes of baking time. A microplane zester makes quick work of getting fine lime zest, and a good citrus juicer helps you get the most juice from your limes.
Don't have a zester? Use the smallest holes on a box grater, being careful to only grate the green part of the peel, not the bitter white pith underneath.
Storage
Store these Key Lime Pie Bars covered in the refrigerator for up to 5 days. They actually improve in flavor after the first day as the lime flavor develops. For longer storage, wrap individual bars in plastic wrap and freeze for up to 3 months.
When serving frozen bars, let them thaw in the refrigerator for about 30 minutes before serving. They're also delicious served slightly frozen on hot summer days – almost like a lime popsicle in bar form!
The Secret I Learned the Hard Way For Perfect Key Lime Pie Bars (So You Don’t Have To)
The first time I made Key Lime Pie Bars for a summer potluck, I was in a rush—cracked cold eggs straight from the fridge, whisked everything like I was beating a rug, and hoped for the best. What came out was... well, not the creamy, dreamy bars I’d imagined. That’s when I learned a little trick that changed everything: always let your egg yolks come to room temperature and stir gently.
It keeps the filling silky-smooth, never curdled or tough. And here’s another thing I’ve learned—Key Lime Pie Bars are only as good as the limes you use, so give that juice a taste first. Some batches are more tart than others, and a tiny adjustment can make a world of difference. Now every time I make them, I think back to that first flopped batch—and feel grateful for the lesson baked right in.
FAQ
How long can key lime pie sit out?
Key lime pie or key lime bars should not sit out at room temperature for more than 2 hours. After that, bacteria can begin to grow, especially in warmer environments. Always refrigerate leftovers promptly. If you're serving them at a party, keep them chilled until just before serving to maintain freshness and food safety.
What are some fun facts about key limes?
Key limes are smaller and more aromatic than regular limes, with a tart, floral flavor. They're also known as Mexican or West Indian limes. Unlike Persian limes, key limes have yellowish juice and thin, pale green skin. They were named after the Florida Keys, where they became a staple in Southern desserts like the iconic key lime pie.
Why did my key lime pie crack?
Cracks in key lime pie or bars usually mean the filling was overbaked. The filling only needs to be set with a slight jiggle in the center—it continues to firm up as it cools. Baking too long causes the custard to tighten and split. Always monitor closely during baking and remove once it’s just set.
How to store lime bars?
Store key lime bars covered in the refrigerator for up to 5 days. Use an airtight container or cover the baking pan tightly with plastic wrap. They taste even better the next day as the flavors meld. For longer storage, freeze individual bars wrapped in plastic and foil, then thaw in the fridge before serving.
Why These Key Lime Pie Bars Deserve a Spot in Your Dessert Lineup
These Key Lime Pie Bars truly embody everything we love about the iconic Florida dessert—zesty, creamy, and nestled on a buttery graham cracker crust. They’re easy enough for a beginner but special enough to impress at any gathering. Whether you serve them after a backyard barbecue or bring them to a holiday party, they never fail to bring that wow-factor with every bite.
If you’re already dreaming of your next sweet fix, don’t miss our fruity Strawberry Shortcake Ice Cream Bar or these dreamy Peach Cheesecake Bars—both are perfect complements to the bright, summery vibe of these bars. So grab those limes and get baking—your dessert table is about to get a whole lot sunnier.Why These Key Lime Pie Bars Deserve a Spot in Your Dessert Lineup
Related
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Pairing
These are my favorite dishes to serve with this Key Lime Pie Bars Recipe:
Key Lime Pie Bars Recipe
Equipment
- 9x13 baking pan Metal preferred for even baking
- Citrus juicer Helps extract max juice easily
- Microplane/zester For fine lime zest
- Parchment paper For easy removal and clean cuts
- Mixing bowl Medium size
- Whisk For smooth filling
Ingredients
For the Crust:
- 1½ cups Graham cracker crumbs About 12 full-size crackers
- ⅓ cup Granulated sugar
- 6 tablespoon Unsalted butter Melted
- 1 pinch Salt
For the Filling:
- 4 Egg yolks Room temperature
- 14 oz Sweetened condensed milk 1 standard can
- ½ cup Key lime juice Fresh or bottled (see notes)
- 2 tablespoon Lime zest From 4–5 limes
- ¼ teaspoon Vanilla extract Optional
- 1 pinch Salt Enhances flavor
Optional Garnish:
- Whipped cream Optional topping
- Lime zest For extra flavor
- Lime slices For presentation
Instructions
- Preheat oven.
- Line pan with parchment paper.
- Mix graham cracker crumbs, sugar, melted butter, and salt for crust.
- Press crust mixture into pan and bake until golden.
- Whisk egg yolks, condensed milk, lime juice, zest, vanilla, and salt until smooth.
- Pour filling over crust and bake again.
- Let bars cool to room temperature.
- Chill in the fridge for 2 hours.
- Cut into bars and serve with optional toppings.
Hyo North says
I’m a bit confused about this recipe. Mainly about the size of the pan. You said that it is a 9 x 13. The picture looks more like a 9 x 9 or 8 x 8. I made the filling and it is very small for a 9 x 13. The filling is super good though. Is it Phil going to rise and get taller?
Ashley says
Great question, Hyo! The filling doesn’t rise much, so if you prefer thicker bars, a 9×9 or 8×8 pan actually works better than a 9×13. The flavor will still be spot on, just a bit thinner in the larger pan. I’ll make a note to clarify that in the recipe; and I’m so glad you loved the filling!
Amanda Mason says
Am I missing something??? What temp are you supposed to cook it at?
Ashley says
The oven temperature should be 350°F (175°C) which is mentioned at the start of the instructions. Looks like the little "preheat your oven to 350°F" line might’ve gotten tucked away and overlooked. I’ll make sure it’s clearer in the steps. Sorry for the confusion, and I hope that helps you bake up the perfect batch!