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Keto lemon bars are the low carb dessert that will impress all your friends. With a golden shortbread crust and creamy, tart filling, these little squares are made for lemon lovers!
Great news: I’m pregnant (yay)! Bad news: I have gestational diabetes (boooo). I suspect it’s because I have a serious sweet tooth and crave dessert ALL THE TIME. I’m adding these keto lemon bars to my arsenal as a diet-friendly dessert that makes me feel better about the whole situation.
Let’s be real: Pregnancy is hard, y’all. This one was tougher because I already have two kids to chase around, and less time (or motivation?) to devote to cooking. I already managed GDM once before with my second pregnancy, though, so at least I’ve been here before—and now I’m renewing my motivation to hop back on the low-carb train. (Which means skillet pizza and salads are on heavy rotation!)
What’s a treat lover to do? Enter: These mind-blowing keto lemon bars. I’ve made plenty of versions of this dessert in the past, both homemade and from a box, and this recipe tastes deceptively close to the original. It’s not just “keto” good, either—I’m talking tasty enough that even your non-keto friends will love them! (A tested fact in my household!)
What makes these keto lemon bars the best
These keto lemon bars create the same tart, creamy filling and golden shortbread crust as the higher-carb versions you’ll find on the internet. This recipe simply swaps in low-carb ingredients like almond flour, better fats, and a low-glycemic sweetener so you won’t feel like taking a nap right after you eat one.
Not only that, this recipe upgrades the existing low carb lemon bars out there that require both powdered and granulated sweeteners (because who always has both on hand?! Not me). You only need granulated in this recipe, but if you just dumped it into the filling you could get gritty bars in the end. We take a shortcut by making our own powdered sweetener in the blender (I use my trusty Vitamix) before tossing in the remaining ingredients and buzzing them into a silky smooth filling.
A more balanced lemon bar recipe
Lots of lemon bars taste extremely sweet or sour to the point of making you pucker! These keto lemon bars are a delicious balance between the sweet xylitol and tangy lemons. You can add up to 1/2 cup additional sweetener to the filing and additional lemon juice or zest, but I find these perfect as-is. It’s a perfect recipe for keto folks who like something sweet without the burn you might normally find in desserts that contain sugar alcohols.
Ingredients & tools for keto lemon bars
Despite their amazing flavor, these keto lemon bars require just a few simple ingredients:
Almond flour: With a nutty flavor, it makes a perfect shortbread crust. Here’s the one we used, which I love for all-purpose keto baking.
Xylitol: Many keto lemon bars recommend erythritol, and you could still use it here, but I chose xylitol this time around. Not only does it taste remarkably similar to sugar, it’s good for your teeth (but toxic to dogs, so watch out if you have furry friends around!). Go for birch xylitol if you can, and skip the corn-derived stuff.
Fresh lemons and lemon zest: Yeah, you could probably use bottled lemon juice for this recipe, but it won’t taste quite the same—you’ll miss out on that extra zip that fresh citrus delivers.
Grass-fed butter: Shortbread needs butter! If you must go dairy-free, though, you could melt the equivalent amount of coconut oil. Ghee would also taste amazing here.
Eggs: They serve the same purpose as they would in regular lemon bars: Eggs help the filling set and add a golden hue from their rich yolks.
Don’t forget the right kitchen tools! A high-powered blender like the Vitamix makes the filling quick and easy, but you can also easily use a mixing bowl and whisk. Plus, a microplane will help you zest lemons with ease.
Keto lemon bars FAQ
Will a different sweetener work?
I would only recommend erythritol as an alternative sweetener here. Blends like Swerve or Lakanto would also be good. You could use your favorite sugar alcohol, but they all have slightly different properties and could affect the fragility of your keto lemon bars after cooling.
Could I use more sweetener than what the recipe calls for?
I like a tart lemon bar (and less sugar alcohol burn), so there isn’t as much sweetener in this keto recipe as some folks may prefer. You can add up to 1/2 cup more sweetener to the filling if you like!
I have a metal pan instead of a glass one, can I use it instead? What about a 9x9 pan?
I had a glass 8x8 pan already, so the recipe is optimized for that. However, you could also use a metal pan and/or a 9x9 pan. Look for browning and “setting” sooner if you use these options, since the layers of crust and filling will be thinner and metal conducts heat better in the oven.
Can I substitute bottled lemon juice for these lemon bars?
You could, but I wouldn’t recommend it. The fresh zest makes a huge difference, plus the flavors taste fresher. If you must go with bottled lemon juice, try it with a dash of lemon extract like this one. (Though I haven’t tested this for myself.)
I have a nut or dairy allergy. Can I substitute coconut flour or coconut oil in this recipe?
Coconut oil will work, but coconut flour rarely makes a good 1:1 swap for almond flour. Consider using sunflower seed or sesame flour instead, or try your favorite coconut flour shortbread crust and watch it closely in the oven.
How do I turn keto lemon bars into lime bars?
Easy! This recipe uses volume measurements instead of a number of lemons, so substitute the same amounts for limes. Add a touch of spirulina or green food coloring if you want them to look more green and lime-ey.
What’s the best way to store keto lemon bars? Do they freeze well?
The food safety fiend in me says to store your lemon bars in a covered container in your fridge. However, I’ve also left them totally uncovered on the counter with no issue. And yes, you can freeze them! Add the finished, sliced lemon bars to a parchment-lined baking sheet and freeze them until solid. Then, you can pop them in a freezer bag or covered container and thaw gently when you’re ready to enjoy them again.
Approximate nutrition facts per serving (1 bar, or 1/12 of this recipe):
Saturated Fat: 4g
Total Carbs: 17g
Sugar Alcohols: 12g
Net Carbs: 2.4g