Key Lime Pie Bars Recipe
These bright and tangy Key Lime Pie Bars are everything you love about a traditional key lime recipe—creamy filling, graham cracker crust, and that sunny citrus kick—packed into easy, party-ready squares.
They’re the kind of citrus dessert bars you bring to a cookout “just to have something sweet,” and they disappear before the burgers hit the grill. With a buttery graham cracker crust, silky lime custard filling, and a cool whipped topping, this Key Lime Pie Bars Recipe is made for summer dessert bars, baby showers, and any Tuesday that needs a little tropical mood boost.
Meet Your New Favorite Citrus Dessert Bar
Key lime pie bars are simply key lime pie baked in a 9×13 pan and cut into squares. Same classic flavor, less fuss. You get all the tangy key lime bars flavor of the Florida Keys—bright, citrusy, and creamy—without wrestling a pie crust or worrying about perfect slices.
I’m a 50-year-old mom who grew up in the Midwest and fell in love with key lime pie on a trip to Florida in my twenties. I still remember eating a slice while sitting on a dock, feet dangling over the water, thinking, “Why does this taste like sunshine?” These baked key lime bars are my go-to way to bring that feeling home, especially when the weather can’t make up its mind.
What makes this lime pie bar recipe extra special?
- A thick, buttery graham cracker crust that doesn’t crumble into dust when you pick it up
- A creamy lime filling that’s smooth, not eggy, with a bright but balanced flavor
- Just the right amount of tartness so it’s refreshing, not puckering
- A whipped cream topping that softens the tang and makes each bite feel like a little cloud
They’re also surprisingly simple. No mixer needed for the crust, and the filling comes together in one bowl. If you can stir, you can make these key lime squares.
Why You’ll Love This Recipe
- Perfect for parties and potlucks – These party dessert bars slice neatly and travel well in the pan.
- Bright, tangy flavor – Real lime juice and zest give you classic, tangy key lime bars with a tropical twist.
- Easy, everyday ingredients – Everything comes from a regular grocery store; no fancy baking supplies required.
- Make-ahead friendly – The bars need to chill, which means you can (and should) make them the day before.
- Beautiful presentation – Pale green lime custard bars topped with whipped cream and lime zest look like they came from a bakery.
- Simple technique – No water bath, no special thermometer, just whisk, bake, and chill.
- Customizable – Turn them into coconut tropical dessert bars, gluten-free bars, or mini bites for dessert platters.
- Crowd-pleaser – This easy lime dessert hits that sweet-tart balance both “not-too-sweet” folks and sugar lovers enjoy.
Ingredients
You’ll need simple pantry and fridge staples for these graham cracker crust bars. Here’s exactly what to grab.
For the Graham Cracker Crust
- 2 cups graham cracker crumbs (about 16 full sheets; you can crush them in a zip-top bag)
- 1/3 cup granulated sugar
- 1/2 cup unsalted butter, melted (1 stick)
- 1/4 teaspoon fine sea salt (helps balance the sweetness)
For the Creamy Lime Filling
- 2 cans (14 ounces each) sweetened condensed milk
- 4 large egg yolks (room temperature if possible)
- 3/4 cup key lime juice (fresh if you can; bottled like Nellie & Joe’s is a great backup)
- 2 tablespoons finely grated lime zest (from key limes or regular limes)
- 1 teaspoon pure vanilla extract
- 1/4 cup sour cream or full-fat Greek yogurt (adds richness and helps the texture set)
Quick note on limes:
Traditional key lime recipe lovers swear by true Key limes. They’re smaller and a bit more aromatic. But regular Persian limes work very well in these lime custard bars if that’s what you have—your bars will still be bright and delicious.
For the Whipped Topping (Optional but Wonderful)
- 1 cup heavy whipping cream, very cold
- 2 tablespoons powdered sugar
- 1/2 teaspoon pure vanilla extract
- Extra lime zest or thin lime slices for garnish
Directions
You’ll use a 9×13-inch baking pan for these baked key lime bars. Line it with parchment and leave an overhang so you can lift the bars out later. It makes cutting clean squares much easier.
1. Preheat and Prep the Pan
Preheat your oven to 350°F (175°C).
Line a 9×13-inch pan with parchment paper, letting it hang over the long sides like little handles. Lightly coat the parchment and exposed sides of the pan with nonstick spray. This keeps the graham cracker crust from sticking or breaking.
2. Make the Graham Cracker Crust
In a medium bowl, stir together the graham cracker crumbs, granulated sugar, and salt.
Pour in the melted butter and mix until the crumbs feel like wet sand and hold together when you squeeze a handful. If the mixture seems dry, drizzle in another tablespoon of melted butter.
3. Press and Par-Bake the Crust
Pour the crumb mixture into the prepared pan.
Use your hands or the bottom of a measuring cup to press the crumbs firmly into an even layer, going slightly up the sides if you can. Really press down—this is the secret to crust that doesn’t fall apart.
Bake the crust for 8–10 minutes, just until fragrant and a shade darker. Set aside to cool slightly while you prepare the filling.
4. Mix the Creamy Lime Filling
In a large bowl, whisk the egg yolks for 30–45 seconds until slightly thickened and smooth.
Add the sweetened condensed milk and whisk until the mixture looks uniform and glossy.
Stir in the sour cream (or Greek yogurt), vanilla, lime zest, and key lime juice.
Whisk until everything is well combined and you don’t see streaks. The filling will look a bit runny—that’s exactly right. It thickens as it bakes and cools.
5. Pour and Smooth
Pour the creamy lime filling over the warm crust.
Use a spatula to spread it into an even layer, nudging it gently into the corners. Try not to bang the pan around; you don’t want extra bubbles in the custard.
6. Bake Until Just Set
Return the pan to the oven and bake for 15–18 minutes.
You’re looking for edges that are set and tiny bubbles forming around the sides. The center should still have a slight wobble when you jiggle the pan—think Jell-O, not liquid.
If you see big cracks forming, it’s likely a bit overbaked. Don’t panic. The whipped topping will cover them, and the bars will still taste great.
7. Cool, Then Chill Completely
Let the pan cool on a wire rack until it reaches room temperature, about 45–60 minutes.
Cover the pan loosely (a layer of foil is fine) and refrigerate for at least 3 hours, or overnight for the cleanest cuts and best texture. The chill time is where the magic happens; the lime custard bars firm up and slice beautifully.
8. Make the Whipped Topping
Once the bars are fully chilled, add the cold heavy cream, powdered sugar, and vanilla to a chilled mixing bowl.
Using a hand mixer or stand mixer, whip on medium-high until soft to medium peaks form. You want it fluffy but still spreadable.
9. Top, Garnish, and Slice
Lift the chilled bars out of the pan using the parchment overhang and set on a cutting board.
Spread the whipped cream evenly over the top, then sprinkle with fresh lime zest or decorate with thin lime slices.
Use a sharp knife to cut into 16 larger squares or 20–24 smaller party dessert bars. Wipe the knife clean between cuts for sharp edges and tidy key lime squares.
Servings & Timing
- Yield: About 16 large bars or 20–24 smaller bars
- Prep Time: 20 minutes
- Bake Time: 23–28 minutes (including crust and filling)
- Chill Time: At least 3 hours (overnight is even better)
- Total Time: Around 4 hours, mostly hands-off
These key lime dessert bars are perfect when you need a make-ahead easy lime dessert. I like to bake them the night before, chill overnight, and add the whipped cream a couple of hours before serving.
Fun Variations to Try
You know what? Once you’ve made these once, you’ll start dreaming up your own twists. Here are some favorites from my kitchen:
- Coconut Tropical Dessert Bars – Stir 1/2 cup sweetened shredded coconut into the crust, and sprinkle more on top before serving.
- Gluten-Free Key Lime Bars – Use gluten-free graham crackers or gluten-free cookie crumbs for the crust.
- Lime Cheesecake Bars – Add 4 ounces softened cream cheese to the filling and whisk until smooth for a richer, cheesecake-style texture.
- Extra Tangy Key Lime Bars – Add an extra 2 tablespoons lime juice and a pinch more salt in the filling for a bolder citrus punch.
- Mini Party Dessert Bites – Bake the crust and filling in a lined mini muffin tin for bite-size summer dessert bars.
- Berry-Topped Lime Bars – Garnish each bar with a fresh raspberry, blueberry, or slice of strawberry for color and a sweet contrast.
Storage & Reheating (Well…Re-Chilling)
These bars are a chilled dessert, so think refrigerator and freezer instead of reheating.
- Fridge: Store key lime pie bars in an airtight container in the refrigerator for up to 4 days. If they’re topped with whipped cream, they’re best within 2–3 days.
- Freezer: For longer storage, freeze the bars without the whipped topping. Wrap the whole slab (or individual bars) tightly in plastic, then foil, and freeze for up to 2–3 months.
- Thawing: Thaw overnight in the fridge. Add whipped cream and garnish just before serving.
- Make-Ahead Tip: You can bake and chill the bars up to 2 days ahead. Whip the cream the day you plan to serve for the best texture.
Notes from My Kitchen
- Use room temperature yolks – They whisk more easily into the condensed milk and give a smoother creamy lime filling.
- Don’t skip the zest – The zest carries so much flavor and gives these lime pie bar recipe results that taste like the real Florida Keys.
- Press that crust hard – I know I sound like a broken record, but pressing the crumbs firmly into the pan is the difference between sturdy bars and a sandy mess.
- Key limes vs. regular limes – When I can’t find Key limes (or I don’t feel like juicing twenty tiny limes), I use regular limes or bottled key lime juice. Flavor is still bright and citrusy.
- Color note: I don’t add green food coloring, so these citrus dessert bars are a natural pale yellow-green. If you like a faint green hue, you can add a drop or two, but it’s not needed for taste.
- Serving tip: These bars taste best cold but not icy cold. Let them sit at room temperature for 10–15 minutes before serving for the creamiest texture.
FAQs
Can I use regular limes instead of Key limes?
Yes. Regular Persian limes work very well in this Key Lime Pie Bars Recipe—your bars will be a touch less floral but still wonderfully tangy.
Can I make these bars without sour cream or Greek yogurt?
You can, but the texture will be a bit firmer and less creamy; if you skip it, reduce the baking time by 2–3 minutes so the lime custard doesn’t over-set.
Why did my filling crack on top?
Cracks usually mean the bars baked a bit too long or cooled too fast. The good news: whipped cream covers cracks, and the flavor is still fantastic.
How do I get clean, neat slices?
Chill the bars fully, then use a sharp knife and wipe the blade clean between each cut. A warm knife (run under hot water and dried) also helps.
Can I halve this recipe?
Yes, bake it in an 8×8 or 9×9 pan. The crust and filling thickness will change slightly, so start checking a couple of minutes earlier.
Are these safe to sit out at a party?
They can sit at room temperature for about 2 hours. After that, slip them back into the fridge so the creamy lime filling and dairy stay safe and firm.
Can I skip the whipped topping?
You can serve them plain if you like extra tang, or dust them lightly with powdered sugar or top with a few dollops of canned whipped cream before serving.
Conclusion
These Key Lime Pie Bars pack all the sunshine of a Florida vacation into a simple pan of tangy, creamy, graham-cracker-crusted goodness. They’re easy to make, easy to transport, and always one of the first desserts gone from the table.
If you try this Key Lime Pie Bars Recipe, let me know how it went—tell me if you served them for a backyard BBQ, a birthday, or just because. And if you love citrus desserts, poke around my other bar and pie recipes; there’s a lemon bar cousin waiting to keep these company in your fridge.
Key Lime Pie Bars
Ingredients
- 2 cups graham cracker crumbs about 16 full sheets, finely crushed
- 1/3 cup granulated sugar for crust
- 1/2 cup unsalted butter melted (1 stick), plus 1 tablespoon more if needed
- 1/4 teaspoon fine sea salt for crust
- 2 cans sweetened condensed milk 14 ounces each
- 4 large egg yolks room temperature if possible
- 3/4 cup key lime juice fresh if possible; bottled like Nellie & Joe’s is a good backup
- 2 tablespoons lime zest finely grated, from key limes or regular limes
- 1 teaspoon pure vanilla extract
- 1/4 cup sour cream or full-fat Greek yogurt
- 1 cup heavy whipping cream very cold
- 2 tablespoons powdered sugar
- 1/2 teaspoon pure vanilla extract for whipped topping
- lime zest or thin lime slices for garnish
- nonstick cooking spray for greasing the pan
- parchment paper to line the pan with overhang
Instructions
- Preheat the oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, letting it hang over the long sides to create handles. Lightly coat the parchment and any exposed sides of the pan with nonstick cooking spray.nonstick cooking spray, parchment paper
- In a medium bowl, stir together the graham cracker crumbs, granulated sugar, and fine sea salt. Pour in the melted butter and mix until the crumbs are evenly moistened and feel like wet sand. If the mixture seems dry, drizzle in up to 1 tablespoon more melted butter.2 cups graham cracker crumbs, 1/3 cup granulated sugar, 1/2 cup unsalted butter, 1/4 teaspoon fine sea salt
- Pour the crumb mixture into the prepared pan. Use your hands or the bottom of a measuring cup to press the crumbs firmly into an even layer, going slightly up the sides if possible. Bake for 8–10 minutes, until fragrant and just a shade darker. Set aside to cool slightly while you prepare the filling.
- In a large bowl, whisk the egg yolks for 30–45 seconds until slightly thickened and smooth. Add the sweetened condensed milk and whisk until the mixture looks uniform and glossy. Whisk in the sour cream (or Greek yogurt), vanilla, lime zest, and key lime juice until well combined and no streaks remain. The filling will be pourable; it will thicken as it bakes and cools.2 cans sweetened condensed milk, 4 large egg yolks, 3/4 cup key lime juice, 2 tablespoons lime zest, 1 teaspoon pure vanilla extract, 1/4 cup sour cream
- Pour the creamy lime filling over the warm graham cracker crust. Use a spatula to spread it into an even layer, gently nudging it into the corners without banging the pan to avoid excess bubbles.
- Return the pan to the oven and bake for 15–18 minutes, until the edges are set and tiny bubbles form around the sides. The center should still have a slight wobble when you gently jiggle the pan, like Jell-O rather than liquid. If large cracks appear, it is slightly overbaked but still fine to serve.
- Place the pan on a wire rack and let the bars cool to room temperature, about 45–60 minutes. Cover the pan loosely (with foil or a lid) and refrigerate for at least 3 hours, or overnight, until fully chilled and set.
- Once the bars are fully chilled, add the cold heavy cream, powdered sugar, and vanilla to a chilled mixing bowl. Using a hand mixer or stand mixer, whip on medium-high speed until soft to medium peaks form; the cream should be fluffy but still spreadable.1 cup heavy whipping cream, 2 tablespoons powdered sugar, 1/2 teaspoon pure vanilla extract
- Use the parchment overhang to lift the chilled slab of bars out of the pan and onto a cutting board. Spread the whipped cream evenly over the top. Garnish with extra lime zest or thin lime slices. Cut into 16 large or 20–24 smaller bars, wiping the knife clean between cuts (a warm knife helps achieve neat slices). Serve chilled.lime zest or thin lime slices
Notes
Tips: Use room-temperature egg yolks for a smoother filling, and do not skip the lime zest for full flavor. Press the crust very firmly so it holds together when sliced. Bars taste best served cold but not icy—let them sit at room temperature 10–15 minutes before serving.
