Deliciously silky Key Lime Pie Bars with the perfect sweet-tart filling, crisp and buttery graham cracker crust, and sky-high whipped cream. These are truly the perfect summer dessert.

This is truly the silkiest key lime filling with the perfect ratio of sweet and sour flavors. You’ll never need another key lime pie bar recipe!

The Ultimate Key Lime Pie Bars

I am a confessed non-lover of citrus desserts, but honestly these key lime pie bars have made me into a believer! I didn’t grow up loving lemon bars or lemon meringue pie, so how much I enjoyed these bars took me completely by surprise.

I’m a chocolate dessert gal through and through, but these are truly the perfect pie bars for summer. I could not get over how perfectly the flavors play together! The sweet and salty graham crackers with the bright and rich filling, topped with a stable and tangy whipped cream topping that won’t deflate over time.

If you’re tasked with bringing a dessert to your next party or BBQ, it has to be these key lime pie bars! They always impress and are so easy for feeding a crowd.

Follow all my recipe tips & tricks below and you’ll be baking like a pro with the result being perfect pie bars every single time!

How to Make Key Lime Pie Bars

I always recommend using a metal baking pan here as it conducts heat more evenly. Do not use a glass baking dish!

Tools Needed

• 8×8 Baking Pan
• Mixing Bowls
• Hand Mixer
• Food Processor
• Citrus Juicer

Ingredients & Substitutions

• Key limes. Obviously fresh key limes are best here! You’ll need about 25 key limes to get 1 cup of juice. If you can’t find fresh key lime juice, this is the brand of shelf-stable juice I use.
• Sweetened condensed milk. I always use Eagle Brand condensed milk as I think it’s the best quality.
• Graham cracker. I cannot stress enough how important it is to use high-quality graham crackers here! You could also swap in cookies like biscoff, ginger snaps, or vanilla wafers.
• Egg yolks. This recipe calls for more egg yolks than your typical recipe, but I think the richness of the yolks tempers the sour key lime juice and makes such a huge difference in flavor and texture!
• Cream cheese. This may not be strictly traditional, but I love the tang of the cream cheese in the filling and the whipped cream.
• Butter. I like to use salted butter for the crust to help balance out some of the sweetness.
• Heavy cream. Make sure your heavy cream is cold when making the whipped cream.
• Sugar. You’ll need granulated sugar and powdered sugar for the crust and whipped cream, respectively.

The Process

1. Make the crust. In a medium mixing bowl, fold the graham cracker crumbs, sugar, and melted butter together until a sandy mix forms and the crumbs clump together in your hand when pressed. Spread the crumb mixture evenly in the prepared baking pan and press them into an even layer. You can use a small measuring cup to press the crumbs into the pan. Bake for 10 minutes, then let the crust cool.
2. Whip the egg yolks. Add the egg yolks, lime zest, and vanilla to a large mixing bowl. Using an electric hand mixer, beat the egg yolks until they’re pale and fluffy, a full 3 minutes.
3. Finish the filling. Add the cream cheese and beat for another 2 minutes, until no clumps remain. Beat in the sweetened condensed milk, lime juice, and salt on low until the mixture is very smooth.
4. Bake. Pour the filling into the cooled crust and bake for 20 minutes, until the filling is set but jiggles slightly. Let the pie bars cool at room temperature for 30 minutes, then refrigerate for at least 4 hours or overnight.
5. Make the topping. In a medium mixing bowl, use a hand mixer to beat the cream cheese with the powdered sugar until smooth. Stream in the heavy cream and beat until medium-stiff peaks form. Use a small offset spatula to spread the whipped cream in an even layer over the bars. Refrigerate uncovered for 30 minutes.
6. Cut and serve. Run a knife around the edge of the bars to loosen them, then use the parchment overhang to pull the bars from the pan. Use a knife heated with hot water to make clean slices and cut the bars into 9 or 16 pieces. Top with lime zest and decorative lime slices.

Making the Perfect Key Lime Pie Bar Crust

While the filling is the star of the show, the crust is an incredibly important supporting role! It’s really easy to end up with sandy, flavorless graham cracker crust, so here are my best recommendations for making the perfect crust every time.

Use quality graham crackers. I CANNOT stress this enough. When I tested this recipe, used some bargain brand graham crackers and they were flavorless garbage, I was so sad. Spring for the more expensive brands (hello, Nabisco!). I also really love the graham crackers from Trader Joe’s.

Don’t grind the graham crackers too fine. This is also an important one. To give the crust nice texture, it’s okay to have some non-uniform crumbs and pieces. I start by snapping the graham crackers into pieces and then just pulsing them in the food processor until they’re broken down. Pulsing them keeps them from being too fine.

Use enough butter. This is not the place to cut down on the butter! You really need enough to moisten the crumbs and hold everything together. When you squeeze the mixture together in your palm, it should hold together.

Really tamp the crust down. When you press the crust into the prepared pan, really press it in there! I like using a small measuring cup to press the crumbs into the pan, thanks to its flat bottom. If you don’t press it enough, the crust will fall apart when it comes time to cut the key lime pie bars.

Recipe Tips & Tricks

You have to whip the egg yolks! This is a non-negotiable. They need a full 3-minutes of whipping before you start adding the other ingredients. This ensures a light and silky smooth texture in the filling.

Use the right temperature ingredients. If the recipe says ‘cold’ or ‘room temperature’ for certain ingredients, follow those instructions! For instance, cold whipped cream whips better, but room temperature yolks and cream cheese blend together more easily. Don’t skip these important cues.

Fresh key lime juice is best. Obviously fresh key limes are best here! You’ll need about 25 key limes to get 1 cup of juice. If you can’t find fresh key lime juice, this is the brand of shelf-stable juice I use.

Do not over-bake the filling. Even if the filling is quite jiggly, I promise you it’ll set up as it cools! You only need the bars in the oven briefly to bring up the temperature to ‘cook’ the yolks. It will still be jiggly when you remove it from the oven, but it will set when it chills.

Whip the whipped cream to medium-stiff peaks. This means that the whipped cream holds shape and is spreadable (see photos above). This ensures that the whipped topping doesn’t deflate and will hold up for days in the fridge.

Storage Instructions

Any leftover key lime pie bars can be stored in an airtight container in the fridge for up to 5 days. These hold up really well, so they’re easy to make in advance for BBQs or parties.

If you plan to freeze the bars, don’t top them with the whipped topping. Let the bars chill for several hours, then remove them whole from the pan (don’t cut). Wrap them well in plastic wrap and store them in a freezer-safe ziplock bag for up to 3 months. Defrost overnight in the fridge before adding the whipped topping.

Key Lime Pie Bars FAQs

Can I double the recipe?

Yes! Except I recommend baking it in 2 separate 8×8 pans instead of a 9×13. It’s too easy to overcook the filling.

I don’t have fresh key limes, what can I use instead?

Obviously fresh key limes are best here! You’ll need about 25 key limes to get 1 cup of juice. If you can’t find fresh key lime juice, this is the brand of shelf-stable juice I use.

Why did my key lime pie bars crack?

The bars are most likely over-baked and the filling is possible over-whipped. You want to whip the egg yolks, but then quickly mix in the remaining ingredients. When baking, the filling should not be liquid but have a firm, custard-like consistency after baking.

Can I use regular limes?

You can definitely use the lime zest, but if you’re not using key lime juice I would recommend a 50/50 split of fresh lime and lemon juice.

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Key Lime Pie Bars are the epitome of summer! The perfect sweet-tart filling, crisp and buttery graham cracker crust, and sky-high whipped cream. If you do try this recipe, I’d love to hear about it! Leave a comment with a star rating below. Be sure to subscribe to my weekly newsletter and never miss a new recipe! You can also snap a photo & tag @JENNYGOYCOCHEA on Instagram. I LOVE hearing about & seeing your SMF creations!

More Bar Recipes to Try

Chocolate Chip Cookie Bars
Marbled Cheesecake Brownies
Apple Cheesecake Bars
Skillet Brookies

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