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 adore key lime anything — so good!
Lime + low carb = heaven. Thanks so much for sharing this recipe!
I would’ve never thought to use almond flour for the crust. That sounds a yummy and healthy alternative to a classic recipe. It’ll make me feel a little bit less guilty when after I eat the whole pan… I can’t wait to try this!
I am wondering if these have ever been made using your condensed milk recipe with coconut milk vs. heavy cream. Unfortunately the key lime portion is not baking or rising. I’m on about 40 minutes of baking and hoping the key lime portion of the bar cooks. I’ve lowered the oven to 300. My Viking Range runs pretty true. I’m thinking it’s the coconut milk in the condensed milk. Bad idea to do this on Christmas Eve Eve! LOL
It could be that, certainly, since it’s not nearly as thick as cream.
I have a key lime loving family and these past the test. I fed these to my son. I didn’t tell him they were healthy until he finished his second serving;) Their always afraid I’ve snuck avocados into their desserts 🙂
Glad to hear it!
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!
Wow, seriously??? That’s awesome, thanks!
These are amazing!!! My husband has been begging for a key lime pie and he is diabetic. I made this last night and it was a hit!! I used 3 1/2 limes and it was just right.
So glad to hear it!
Is there anything you can think of that I could use instead of cream cheese! I am not a fan of cream cheese. Possibly Greek yogurt?
The cream cheese gives it structure. Yogurt won’t do that. It doesn’t taste at all like cream cheese.
I’m new to Keto and looking at the key lime recipe, the ingredient swerve do you use granular or confectioner?
Thank You
Lucy
When I just say Swerve, it means the granular (in the same way that if a recipe says “sugar” it means the granular kind).
I changed my mind, THESE are my favorite dessert from you! Wow is all I can say. I served these to my parents and they had no idea they were low carb. Making the sweetened condensed milk does take time but it’s oh so worth it!! Thank you for another amazing recipe
I love these bars! I made them for our 4th of July get together tonight. I had MY dessert and I didn’t feel tempted my the coconut cake I made for other guests. I only made one mistake…I put too much xanthan gum in and my condensed milk was way too thick but I wasn’t going to waste it. Next time I’ll make sure to whisk really well after it cools before adding more. Thank you so much because key lime pie is my absolute face pie!!
So glad you liked it…even with the extra xanthan! 😉
These bars are amazing and phenomenal! My husband LOVES them! I made a batch on Saturday and they are gone already. Making another batch today. Thank you for all these recipes!
I’ve been a key lime pie lover forever. I made these yesterday and believe me, this satisfied my craving that I’ve had for years now! They are really delicious. Mine came out a little more like a cheesecake but I’m not complaining. Great job again, Carolyn!
Carolyn, You’ve outdone yourself. These bars a so good they’re dangerous; I want to eat half the batch instead of just one bar. And the sugar-free sweetened condensed milk recipe works great. I wondered while making it what the resulting reduced volume of cream should be. After adding the swerve to the reduced cream, I ended up with about 1 1/4 cups of sweetened condensed milk and I think I was supposed to end up with just one cup. I needed to add the full amount of xanthan gum to get it thick enough but, mixed with the key lime pie ingredients, it baked up beautifully and bars are delicious! Perfectly zingy with just enough sweet. You’re my low carb hero! Thank you for all the delicious work you do and share with us.
So so happy for the sugar free condensed milk recipe and all the creative recipes to be made with it! The Key Lime bars are devine.
I started this recipe before realizing I only had 1/2 cup sugar-free condensed milk. So I added 1/2 cup powdered swerve into the topping and it came out GREAT!!
Key lime pie is my fave so thank you so much for this!!
Glad it worked!
Omg these are delish! After making the condensed milk I waited patiently for this recipe! Rated A++ by the family too
My crust came out very soft. Is there any way to make it firm up?
Soft as in too gooey? Then they probably didn’t bake quite long enough. You could freeze them if you have to. That might help.
thank you for removing so many carbs with just the right ingredients, especially since I’ve skipped traditional key lime pie for awhile for that very reason
Just ate a piece of key lime pie today thinking how to make one low carb & healthier minus all the sugar. Open my email to see your key lime pie recipe. Perfect timing, thank you! I want just the pie filling, dont even care about crust.
Looking forward to make this with your sugar free condensed milk. Will try the key lime fat bomb & Popsicle recipes also.
Glad that worked out 😉 If you are doing a pie, the filling will probably need to be 1.5 times at least.
Didnt think to look but the key lime pie I ate had 45 carbs per slice…with sugar condensed milk. I about fell out when I looked! No wonder its so darn good, Now to detox from the sugar.
Yay! One of my fave desserts and you made it possible! If I ever win the lottery I’m giving you part because you’ve allowed me to enjoy so many of my favorite desserts! I find I like monkfruit for my sweet supply and it works just as good
Thanks again for this! I’ll be making it this weekend
How long do these keep? I made them just for me so there are quite a bit. Do they freeze?
I haven’t tried freezing them. They can be refrigerated for up to 5 days.
I don’t know what I did wrong but I left it in the refrigerator for 2 days and it’s STILL runny! Ugh! What can I do differently!
You clearly didn’t bake it long enough. Maybe your oven runs cool? Or did you use a different kind of sweetener? Or bake it in a non metal pan?
Did you use the whole recipe for condensed milk? You only use 1 cup of it for this recipe. Maybe that was the problem? Idk