Key Lime Pie Bars
These key lime pie bars have a creamy filling, buttery graham cracker crust, a mellow citrus flavor, and a dreamy layer of homemade whipped cream. This recipe makes a big batch so they’re perfect for sharing!
Who else loves authentic key lime pie? It’s been my absolute favorite dessert since I was 14 or 15 and I had my first slice while on vacation in the Gulf Shores, Alabama.
It was sweet, tart, smooth, and creamy all rolled into one. As an adult, it’s the dessert item I order most at restaurants. Thank goodness I live in South Florida, because key lime pie is everywhere!
Sometimes I want the same sweet-tart flavor in a more portable form. That’s when I make my key lime pie bars. They’re easier to chill, slice, and serve than a traditional pie.
They have a wonderfully creamy key lime filling, the graham cracker crust holds together well, and the homemade whipped cream layer tops them off beautifully.
These bars are one of my favorite things to make when I’m sharing food with the neighbors. Everyone loves them and there are always plenty to go around.
Why I use bottled key lime juice
I used bottled key lime juice on purpose. I’m not squeezing a mountain of tiny key limes for a full pan of bars, and I doubt most people want to do that either. My favorite brand is Nellie & Joe’s because it’s easy to find and works well.
One thing that does bug me, though, is when recipes call something key lime and then quietly use regular grocery store limes. Regular limes (a.k.a. Persian limes) will still give you a good citrus dessert, but they do not taste the same. Key limes have that sharper, brighter flavor that’s more floral and acidic.
If you’ve had real key lime, you’ll be able to tell a difference. Key limes are tiny compared to regular limes, and it takes a while to juice enough to make this recipe. That’s why I opt for bottled.
What keeps the filling smooth and easy to slice
These bars have a creamy filling, but they still need enough structure to hold together. That comes from the cream cheese, egg yolks, and sweetened condensed milk.
Together, they give the filling that soft, smooth texture while still letting it firm up properly in the refrigerator. It’s similar to a custard-like filling that sets up firm but silky smooth.
The cream cheese also changes the flavor in a good way. These still taste like key lime, but they’re not as tart or puckery as a traditional key lime pie.
The other big thing is not overbaking them. The edges should look set, and the center should still have a slight jiggle. The top should stay pale. If it starts to brown, they’ve gone too far.
How to make key lime pie bars
For the best bars, don’t skip these steps!
Bake the crust before adding the filling, use room temperature cream cheese, and give the bars enough chill time. Those three things are really important.
- The crust has to be baked in order to hold up to the thick filling.
- The cream cheese needs to be super soft in order for the filling to be smooth and creamy. Make sure to give it plenty of time to come to room temperature.
- Don’t be tempted to cut the bars early. They need to cool at room temp for a bit then finish cooling in the fridge for several hours. The filling needs to set similar to a cheesecake.
- Line the pan with parchment paper before adding the crust, leaving some overhang on the sides. This creates a sling you can lift the whole batch out with before slicing, which makes cutting much cleaner and easier. (I was out of parchment paper for the photos!)
- For the cleanest slices, run a sharp knife under hot water and wipe it dry before cutting. Wipe the blade clean between each cut. Pulling the knife straight up after each slice can drag the layers. Slide it out horizontally instead.
Make-ahead and storage
These are great made a day ahead. In fact, I think they’re better that way because the filling firms up more and the slices come out cleaner.
Store them covered in the refrigerator for 4-5 days. You can also freeze them, though I prefer to do that without the whipped cream topping if possible.
To freeze, wrap the pan tightly in plastic wrap followed by a layer of foil, or transfer individual bars to an airtight container. They’ll keep in the freezer for up to 3 months. Thaw overnight in the refrigerator before serving.
About the sweetened condensed milk
Make sure you’re using sweetened condensed milk and not evaporated milk. They look similar on the shelf but are completely different. Sweetened condensed milk is thick and syrupy. Evaporated milk is thin and unsweetened, and the filling won’t set properly if you use it by mistake.
Can I use regular lime juice instead of key lime juice?
Yes. The bars will still work, but the flavor will be different. Regular limes are less acidic than key limes, so the bars won’t have quite the same classic key lime flavor. You’ll be making lime bars, not key lime bars. They’ll still taste fantastic!
Can I use fresh key limes instead of bottled key lime juice?
Yes, but you’ll need a lot of them. Fresh key limes are small, seeded, and take more time to juice. If you happen to have some handy, the juice will taste amazing in these bars!
If you’re taking these bars to a picnic or summer potluck, don’t forget to pack a jug of honey lemonade or make a bowl of our colorful sherbet punch to serve with them.
What You’ll Need
For the crust
- 3 cups graham cracker crumbs, about 16 full graham cracker sheets
- ⅓ cup granulated sugar
- 10 tablespoons unsalted butter, ½ cup + 2 tablespoons; melted
For the filling
- 8 ounces block-style cream cheese, softened to room temperature
- 6 large egg yolks
- 28 ounces sweetened condensed milk, 2 (14-ounce) cans
- 1 cup key lime juice, bottled
- 1 heaping tablespoon lime zest
For the whipped cream topping
- 2 cups heavy whipping cream
- ¼ cup powdered sugar
How to Make It
To make the graham cracker crust
- Preheat the oven to 350°F, and grease a 9×13-inch pan or line with parchment paper.
- In a medium bowl, stir together the graham cracker crumbs, and sugar. Add the melted butter and mix until evenly coated and the texture resembles wet sand.3 cups graham cracker crumbs⅓ cup granulated sugar10 tablespoons unsalted butter
- Press the crust mixture firmly and evenly into the bottom of the prepared pan. Use the bottom of a measuring cup to pack it down tightly.
- Bake for 10 minutes, until lightly golden brown and set. Remove from the oven and let cool slightly while you prepare the filling.
To make the filling
- In a large bowl, beat the softened cream cheese until completely smooth and free of lumps.8 ounces block-style cream cheese
- Add the egg yolks and mix until fully incorporated. Pour in the sweetened condensed milk and beat until smooth.6 large egg yolks28 ounces sweetened condensed milk
- Add the key lime juice and lime zest. Mix until fully combined. The mixture will thicken slightly. Pour the filling over the warm crust and spread evenly.1 cup key lime juice1 heaping tablespoon lime zest
- Bake for 20–25 minutes, just until the center is set with a slight jiggle in the middle. Do not allow the top to brown.
- Cool at room temperature for 30–45 minutes, then refrigerate for at least 4 hours or until fully chilled and firm.
To make the topping
- In a large bowl, beat the heavy whipping cream and powdered sugar until stiff peaks form.2 cups heavy whipping cream¼ cup powdered sugar
- Spread the whipped cream evenly over the chilled bars, and add more lime zest if desired.
- Slice into squares with a sharp knife, wiping the blade clean between cuts for neat slices.