These sugar free Key Lime Pie Bars feature a tangy citrus filling and a tender almond flour shortbread crust. They are a popular summertime keto dessert with good reason!
I consider these key lime pie bars as proof that the keto diet is not one of deprivation. Really, people, when you are able to eat something this tangy, this flavorful, this creamy, life is good.
I’ve been doing this for quite some time now and it can still take even me by surprise. Aren’t we the lucky ones, to have discovered this little secret?
Key lime was one of my dad’s favorite flavors, so I always think of him when I make anything with it. I have a classic Keto Key Lime Pie that I know he would have loved. And I am quite certain he would have gobbled down these delicious bars with gusto!
Why you will love these bars
This citrusy keto dessert is somewhere between cheesecake and pie, but easier to make than either of them.
I use the classic technique of mixing egg yolks with sugar free condensed milk. But the added cream cheese allows the filling to set more easily. It’s also a little creamier and has greater volume this way.
The shortbread crust complements the tangy filling perfectly. It’s much the same as my easy keto pie crust, but baked in a square metal pan.
These bars are easy to make, but they do require some chill time to set properly, so have a little patience. Then you have a dessert that has only 2.4g net carbs per serving. You could even afford to eat two of them!
Reader Reviews
“This is so delicious and easy to make. The hard part is sticking to only eating a single serving. Thank you for your wonderful cookbooks and recipes with easy to follow instructions and tips (yep, I read the whole post not just jump to the recipe).” — Cara
“Just thought you ought to know that I used this recipe in a workplace cooking competition where it competed against some very non-keto desserts. I am pleased to say it was declared the winner by a mile! Thank you for creating these delicious recipes that make keto dieting so much easier!” — Gabrielle
“Carolyn, these are wonderful. I made them yesterday, tried them today, and my husband and I both enjoyed them. I used regular limes because that’s what I had. I wasn’t sure about keto baking after the last recipe I made (not from your blog), but now I understand that I have to choose recipes from the right blog… 🙂” — Susan
Ingredients you need
- Almond flour: Coconut flour does not make a very good crust, which is why I prefer to use almond flour. Pecan flour would also be delicious and for a nut-free option, you can use sunflower seed flour.
- Sweeteners: Keep in mind that only erythritol-based sweeteners such as Swerve will produce a crisp crust. And using some BochaSweet or allulose in the condensed milk helps keep it creamy and soft. See the Expert Tips for more sweetener options.
- Condensed milk: You can’t purchase sugar free condensed milk, you need to make it yourself. It’s easy and worth it! Do this first, so you can let it cool before making the filling.
- Cream cheese: I use cream cheese to help thicken the filling and give it a little more substance. It makes it extra creamy, too!
- Key Limes: Key limes are teeny tiny things and it takes quite a few of them to get enough juice. They are a pain to squeeze! So I recommend the bottled juice from concentrate. I found some at the grocery store but it’s also available on Amazon.
- Eggs: You only need the yolks for the custard base of these bars. Don’t waste those egg whites. Use them to make some keto meringues!
- Kitchen staples: Butter and salt.
Step-by-step directions
- Make the condensed milk: Follow the instructions for my easy keto condensed milk and let it cool completely.
- Prepare the crust: In a medium bowl, whisk together the almond flour, sweetener, and salt. Stir in the melted butter until the mixture begins to come together.
- Bake the crust: Transfer mixture into an 8×8 baking pan and press firmly into the bottom. Bake 12 to 15 minutes at 325ºF, until just golden brown around the edges.
- Prepare the filling: In a large bowl, beat the cream cheese and lime zest until smooth. Beat in the egg yolks until well combined. Slowly beat in the condensed milk and lime juice until the mixture is smooth.
- Bake the filling: Spread the filling over the crust and bake 18 to 20 minutes, watching carefully to make sure it doesn’t brown at all. Remove and let cool, then refrigerate at least one hour to firm up.
- Garnish: Top with lightly sweetened whipped cream and lime slices
Expert tips
I found I didn’t need to add any other sweetener to the filling besides the condensed milk. However, if you like things sweeter and less tangy, then feel free to add a tablespoon or two of powdered Swerve or some stevia extract.
Make sure the egg yolks are at room temperature before adding them to the cream cheese. Cold eggs or yolks will make it clump up again and you won’t have a smooth filling.
If you don’t care about authenticity, feel free to use regular Persian limes. The bars will still be delicious!
Sweetener Notes
The only sweetener that will produce a crisp crust is erythritol. Any amount of allulose or BochaSweet will make it much softer so keep that in mind. If you don’t care about crispness, feel free to use your favorite. Allulose will make it brown faster.
The filling really requires some BochaSweet or allulose (in the condensed milk) to have a good, soft consistency. If you use only erythritol based sweeteners, the filling will likely recrystallize as it cools. You can play with the amounts, adding more of the allulose or BochaSweet if you prefer. But it may take longer to set if it contains more allulose.
Frequently asked questions
Although they are slightly sweeter and less tart than regular limes, key limes can be used in keto recipes. The juice has only about 3g of carbs per ounce (two tablespoons).
Because of the creamy filling, these bars should be refrigerated at all times. Store in a covered container and they last up to 5 days in the fridge. They can also be frozen for several months. I would leave off any whipped cream and garnish until you have thawed the bars.
This keto key lime pie bar recipe has 3.4g of carbs and 1g of fiber per serving. That comes to 2.4g net carbs per bar.
More healthy keto lime recipes
Cilantro Lime Cauliflower Rice
Cilantro Lime Cauliflower Rice takes only 5 simple ingredients and has spectacular flavor. This copycat of the famous Chipotle rice goes with all of your favorite healthy dinners.
Keto Key Lime Cheesecake
Keto Key Lime Cheesecake is a tangy sweet dessert recipe that serves just two people. This easy dessert recipe takes only 6 ingredients and 15 minutes to make!
Skinny Keto Margaritas
Look no further for the BEST keto margarita recipe! With 4 simple ingredients, these easy sugar-free cocktails have that classic margarita flavor without the extra carbs.
Key Lime Pie Bars Recipe
Ingredients
Shortbread Crust:
- 1 1/4 cups (132 g) almond flour
- 1/3 cup (78.86 ml) Swerve Sweetener, (old formula)
- 1/4 tsp (0.25 tsp) salt
- 1/4 cup (56.75 g) butter, melted
Key Lime Filling:
- 3 ounces (85.05 g) cream cheese, softened
- 2 tsp lime zest
- 4 large egg yolks, room temperature
- 1 cup (236.59 ml) sugar-free condensed milk
- 6 tbsp (6.09 tbsp) key lime juice
Instructions
Shortbread Crust:
- Preheat the oven to 325ºF.
- In a medium bowl, whisk together the almond flour, sweetener, and salt. Stir in the melted butter until the mixture begins to come together.
- Turn out the mixture into an 8×8 baking pan and press firmly into the bottom. Bake 12 to 15 minutes, until just golden brown around the edges.
- Remove and let cool while preparing the filling.
Key Lime Filling:
- In a large bowl, beat the cream cheese and lime zest until smooth. Beat in the egg yolks until well combined. Slowly beat in the condensed milk and lime juice until the mixture is smooth.
- Spread the filling over the crust and bake 18 to 20 minutes, watching carefully to make sure it doesn’t brown at all. Remove and let cool, then refrigerate at least one hour to firm up.
- Top with lightly sweetened whipped cream and lime slices
Notes
Nutrition
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I make these Key Lime Bars based on your lemon bar recipe. They are so good. Your recipes never disappoint.
So delicious!My husband loved them as well!
This is so delicious and easy to make. The hard part is sticking to only eating a single serving. Thank you for your wonderful cookbooks and recipes with easy to follow instructions and tips (yep, I read the whole post not just jump to the recipe).
We’ve recently started doing low carb for my kiddo, to help with something he had going on, health-wise, and the absolutely LOVED these! Thank you so much!
These were divine! That shortbread crust was to die for.
These are amazing! I am so excited to give them a try! YUM!
Oooh I love tangy and zesty desserts- I feel like the citrus is such a good balance to the sweetness. Thanks for sharing this!
It is GREAT to follow a recipe exactly as written and not feel like you should have tweaked something because it turned out perfectly! I feel like all the “work” to create the best product has really been done and my tastebuds agree! This is absolutely divine!!!
These are delicious! I highly recommend them.
These are fabulous! Used the larger Persian limes and they were tangy enough for my palate. Another winner. Now I will get busy with some holiday cookies. Thanks
so good! a new favorite
I am dying to make these, they look wonderful, especially in our super hot environment. But, I’m on a tiny island in the Caribbean, and there is no sugar free condensed milk here. No one would ever understand why I might want that, Lol. Is there anything that could be substituted for that?
You don’t purchase it… you make it! 🙂 The recipe is linked right in there.
Carolyn, these are wonderful. I made them yesterday, tried them today, and my husband and I both enjoyed them. I used regular limes because that’s what I had. I wasn’t sure about keto baking after the last recipe I made (not from your blog), but now I understand that I have to choose recipes from the right blog… 🙂
Glad to hear it, Susan!
Can I use vegan cream cheese as my husband is lactose intolerant?
Probably but I didn’t test them that way so I can’t guarantee it.
Those look amazing!
These bars were absolutely great! I have already dropped off six bars (socially distanced -curbside) to three friends and three of my children as a pre Xmas treat! It may be my favorite dessert of yours!
I’d love to give this recipe a go, but I have a nut allergy. Is there another option I could use instead of the almond flour? Or a recipe for another base that would work, perhaps?
Sunflower seed flour.
Thanks for your quick reply! I’m new to Keto and I’ve tried many of your recipes! Next time I will use Boca Sweet. I was actually just eating a bar right now and they’re soooo good.
Glad you still like them!
This was wonderful bar but mine came out a bit grainy. I used powdered swerve in my condensed milk. My cream cheese wasn’t softened long enough, could that have been the issue? The flavour is amazing and overall they look great. Is the filling meant to be luscious and creamy? I will try again, these ones taste amazing though!
So since you used only Swerve in your condensed milk, that will happen. Without another sweetener like BochaSweet, allulose, or xylitol, the erythritol will re-crystallize a bit.
Thanks for your quick reply! I’m knew you Keto and I’ve tried many of your recipients! Next time I will use Boca Sweet. I was actually just eating a bar right now and they’re soooo good.
THE BEST KETO DESSERT I’ve made (and I’ve made a lot!) The only change I made was that I used regular limes for the key limes. I also used allulose for the sweetener. These were wonderful. I ended up packaging the individual bars (the 4 or 5 I didn’t eat from the recipe a couple days after baking it) in plastic and storing in the freezer. They’ll be wonderful frozen. The crust is on point and the lime filling is incredible. My husband isn’t a fan of a lot of the keto desserts I make but he loved these and couldn’t tell they were sugar free. Thank you for this amazing recipe!!! Your site is a gold mine!