Showcase the best of summer’s bounty with this beautiful Keto Lemon Blueberry Layer Cake. Tender and sweet, and bursting with flavor, it has a delectable sugar-free cream cheese frosting. And only 4.8g net carbs per slice!
Need more ideas for your summer zucchini? Check out this list of Keto Zucchini Recipes
Lemon and Blueberry: Classic Summer Flavors
This recipe has long been one of my summer favorites because it brings together so many fresh flavors. I tend to favor keto chocolate cake, but the light tangy sweetness of this Keto Lemon Blueberry Cake wins me over every time. And the zucchini adds wonderful moisture and nutrition.
I know that it can be hard to think about turning on the oven in the middle of summer. I get that, I really do, and I have many wonderful easy keto dessert recipes for those of you who just can’t bear the thought.
But if you’re a bakeaholic like me, sometimes you’ve just got to suck it up and bear it. Because you can’t bake gorgeous keto cakes like this one without a little heat. And sometimes nothing will do but a big layer cake with plenty of creamy frosting. So throw open those windows, blast the fans, or jack up the AC, kids. It’s going to get a little hot in here!
★★★★★
Nancy says: “I have made this cake several times and everyone always wants the recipe! It’s so delicious and moist and the lemon and blueberry flavors are such a wonderful taste of spring. Thanks, Carolyn!“
Ingredients and Substitutions
- Zucchini: This adds wonderful moisture and texture to the cake, along with a boost of nutrition.
- Almond flour: I really feel this cake works best with a finely ground almond flour. If you wish to use coconut flour, follow the basic amounts and instructions for my Keto Chantilly Cake.
- Protein powder: As with many baked goods, this helps the cake rise better and hold its shape. You can use whey or egg white protein powder. Plant-based may work as well but I don’t recommend collagen protein.
- Sweetener: I suggest using a granular erythritol-based sweetener in the cake and a powdered sweetener in the frosting. Please see the Sweetener Options for a more detailed discussion.
- Lemon: This cake recipes uses the zest and the juice. You can also bump up the lemon flavor with a little lemon extract.
- Blueberries: Fresh blueberries work best as they don’t bleed into the batter.
- Cream cheese: This is the base for the super creamy frosting!
- Heavy cream: A little heavy cream helps thin the frosting to a spreadable consistency.
- Baking staples: Butter, eggs, baking powder, vanilla, salt.
How to Make Keto Blueberry Lemon Cake
- Drain the zucchini: Salt and drain the zucchini in a sieve, then squeeze out as much moisture as possible.
- Prepare the batter: Whisk the dry ingredients together. Beat the butter with the sweetener until well combined, then beat in the eggs and extracts. Beat in the dry ingredients and lemon juice. Fold in the blueberries.
- Bake the layers: Spread the mixture evenly in two 8-inch round cake pans. Bake until golden brown and firm to the touch.
- Prepare the frosting: Beat the cream cheese and butter together until smooth, then beat in the sweetener, lemon zest, lemon juice, and cream.
- Frost the cake: Spread the top of the first layer with frosting, then add the second cake layer. Spread the remaining frosting over the top and sides.
- Garnish: Decorate with additional blueberries and lemon zest.
Carolyn’s Tips for Success
Squeeze the zucchini very dry so the cake isn’t mushy. You can do this with your hands, squeezing it in your palm and pressing it out in the sieve, or you can wrap it a tea towel and twist it.
Make sure the butter is properly softened! I find I sometimes have to give it a quick 10-second zap in the microwave, because room temperature is not always soft enough. It will beat more smoothly if it’s properly softened (but not melted), and become fluffier when you add the sweetener.
Don’t skip the grated lemon zest in either the cake or the frosting, as it gives the best flavor. You can also add some lemon extract to the cake, if you want more lemon flavor.
The frosting makes enough for the top of each layer and a thin “crumb coat” on the sides. If you want a fully frosted cake, I recommend increasing the frosting by about 30%. This will change the nutritional content.
Sweetener Options
For the cake layers, an erythritol sweetener that doesn’t contain any allulose will work best. Good brands to consider include Impact Sweetener or Lakanto. Sweeteners with any amount of allulose will cause the cake to brown too quickly and it may even taste burnt.
If you wish to cut down on erythritol, try using 1/4 cup and supplementing the sweetness with a highly concentrated sweetener such as pure stevia or monk fruit.
The frosting requires a powdered sweetener to have the right volume and structure. But both erythritol and allulose based sweeteners work.
More Delicious Keto Blueberry Recipes
Keto Lemon Blueberry Zucchini Cake
Equipment
Ingredients
Cake:
- 1 medium (196 g) zucchini, shredded, (about 200g)
- 1/4 tsp salt
- 2 1/2 cups (280 g) almond flour
- 1/2 cup (54 g) unflavoured whey protein powder
- 1 tbsp baking powder
- 1/4 tsp salt
- 1/3 cup (75.67 g) butter, softened
- 1/2 cup (95 g) granular sweetener, erythritol recommended
- 3 large eggs, room temperature
- 1 tbsp lemon zest
- 1/2 tsp vanilla extract
- 1/2 tsp lemon extract, (optional)
- 3 tbsp (45.65 g) freshly squeezed lemon juice
- 1 cup (148 g) blueberries, fresh works best
Lemon Frosting:
- 8 ounces (226.8 g) cream cheese, softened
- 1/2 cup (113.5 g) butter, softened
- 1/2 cup (95 g) powdered sweetener
- 2 tbsp freshly grated lemon zest
- 2 tbsp (30.43 g) freshly squeezed lemon juice
- 2 tbsp (30.43 g) heavy whipping cream
Garnish:
- fresh blueberries
- lemon zest
Instructions
Cake
- Place the zucchini in a sieve and sprinkle with the salt. Toss to combine. Let drain 1 hour and then squeeze out the zucchini to release as much moisture as possible.
- Preheat the oven to 325ºF and grease 2 (two) 8-inch round cake pans very well. Line the bottoms with parchment paper and grease the parchment.
- In a medium bowl, combine the almond flour, protein powder, baking powder and salt.
- In a large bowl, beat the butter with sweetener until well combined. Beat in the eggs one at a time, scraping down the sides of the bowl and the beaters as needed. Then beat in the zucchini, lemon zest, and vanilla extract.
- Beat in the almond flour mixture until well combined, then beat in the lemon juice. If your batter is quite thick, add a little water, 1 tbsp at a time, until a spreadable consistency is achieved.
- Gently fold in the blueberries. Divide the batter between prepared pans and spread evenly to the edges. Bake 30 to 40 minutes, until golden brown around the edges and the top is set to the touch.
- Remove and let cool completely in the pans, then run a sharp knife around the edges to loosen.
Frosting
- In a large bowl, beat the cream cheese and butter together until smooth. Beat in the sweetener until well combined, then beat in the lemon zest.
- Beat in the lemon juice and cream until well combined.
To Assemble
- Place one cake layer on a serving platter and spread the top with about 1/3 of the frosting. Add the second cake layer and spread the remaining frosting over the top and the sides.
- Garnish with additional fresh blueberries and lemon zest.
Nutrition
Are blueberries keto-friendly?
The reality is that any food can be “keto” if you eat small enough amounts of it. But blueberries, while super healthy and full of antioxidants, are not the most keto friendly fruit. 1 cup of raspberries has 15g of carbs and 8g of fiber, but blueberries weigh in at 21g of carbs and only 3.6g of fiber.
Again, it’s not that blueberries are bad for keto diets, but they do have more carbs than you’d think so it’s wise to be conscious of how many you consume. One of the main ways I reduced the carbs in this cake was by cutting back a bit on the blueberries. But don’t worry, you still get plenty of delicious ripe blueberries in every bite. I also cut back on the almond flour and added more protein for a lighter, fluffier cake!
Nutritional Disclaimer
Please note that I am not a medical or nutritional professional. I am simply recounting and sharing my own experiences on this blog. Nothing I express here should be taken as medical advice and you should consult with your doctor before starting any diet or exercise program. I provide nutritional information for my recipes simply as a courtesy to my readers. It is calculated using MacGourmet software and I remove erythritol from the final carb count and net carb count, as it does not affect my own blood glucose levels. I do my best to be as accurate as possible but you should independently calculate nutritional information on your own before relying on them. I expressly disclaim any and all liability of any kind with respect to any act or omission wholly or in part in reliance on anything contained in this website.
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Do you have any suggestions for making this with coconut flour + more eggs instead of almond flour? I usually get headaches when I eat too much almond flour. Thanks!
Okay, here’s what I am thinking. Follow this recipe for the cake part but use 6 eggs and 6 tbsp of butter and then the zucchini. It adds moisture so we have to take it away from somewhere in the recipe. And of course still use the blueberries. https://alldayidreamaboutfood.com/2013/11/vanilla-bean-coconut-flour-cupcakes-and-teaching-children-about-kindness.html
Most excellent suggestion! Thank you so much, Carolyn!
Thanks for the recipe. I used coconut oil for butter, then instead of swerve 1/2 tsp powdered stevia, and a few drops of lemon EO, and egg white protein powder. Then the frosting was coconut cream, stevia, coconut oil, and a little agar agar. It still turned out really tasty and moist.
Amazing! Thanks for sharing your substitutes was looking to make this for a dinner party that had dairy and nut allergic guests. Much appreciated!
anyone ever tried in a 13×9 pan?
I believe some folks have, yes.
Hi – the recipe yield at the top says 1-9″ cake. I believe it should say 2-9″ cakes?
No, it really means in the end the final cake with all the layers and frosting. So 1 cake (even though there are two layers)
Can this be frozen with the frosting on. Too much cake for us
It could. Flash freeze it first before trying to wrap it up, or your frosting will get all smushed.
Do you suggest refrigerating this cake? Sorry if I missed that question being asked already. Tried to read all through the comments! I need to make it tonight to serve tomorrow.
Yes, you should refrigerate any cake with a creamy frosting like this.
Carolyn I’m making this tomorrow! It looks fantastic.
Do you peel the zucchini before shredding?
No, leave all that good healthy skin on there!
Hi! Do you rinse the zucchini shreds to get all of the salt off before using in recipe?
No, you just add less salt in the rest of the cake.
I tried this recipe today and holy cow, is it ever delicious!!!
I used Xylitol as that’s what I had in the house for sweetener. It requires much less Xylitol than this recipe calls for, but that was an easy adjustment. The cake was really moist, really rich, really full of lemony flavour! I love everything lemon, so perhaps I’m biased, but this did not disappoint! I’ve been low carb for years…. and these kinds of treats can start me on a bad path (haha) but clearly a better alternative to the full sugar/flour versions and if I manage to limit my intake then it’s all good (hard not to just wolf this down in one sitting!!!!!)
Oh, also I did this in 6 inch rounds…5 layers. I baked them for a shorter time as a result. Tall and skinny and cute!!! I put blueberries and purple flowers on top!
Thanks for the recipe!!!!!!
Ignore my previous comment! I’m reading on my mobile and it didn’t show me the 1tsp of stevia or another 1/2 cup or swerve right. Thanks!
Hi Carolyn,
Such a great recipe! Quick question – I see swerve listed twice in the cake ingredients. Is it asking for 1/2 cup or 1 cup? Also, I don’t have liquid stevia. Can I leave out?
Thanks!!
Do you use green zucchini or yellow squash?
Green zucchini.
Could yellow squash be used instead? I have family members who are hesitant to try low carb recipes, much less ones that they can tell there’s something “different” about. Thinking the yellow squash would blend in a little better.
Love your recipes! Thank you!!!
Sure, it’s basically the same.
Does this taste like zucchini? I like zucchini, but maybe not a cake that tastes like it.
No, zucchini simply adds moisture to a cake like this.
I have enjoyed several of your desserts! I follow the THM plan and I am just wondering if you have an opinion on how much THM baking blend or a very similiar blend could replace the almond flour?? It would help cost and calorie density! Was hoping someone had already asked that question, but didn’t see it!
It’s tricky, because the baking blend is much drier than almond flour so you risk a dry, crumbly cake. I think you’d maybe want a little less of it. (2 1/2 cups?) but to add another egg to help bind it and give it extra moisture.
Thanks… Do you have any bundt cakes other than the Buckeye?
YES! I have tons, I love my bundt pan. So the question is…what kind do you want? Lemon Poppyseed? https://alldayidreamaboutfood.com/2013/01/lemon-poppyseed-bundt-cake-low-carb-and-gluten-free.html
Chocolate Hazelnut? https://alldayidreamaboutfood.com/2012/10/hazelnut-chocolate-chip-bundt-cake.html
If you want something else, just type “bundt” into the search box here on my blog and you will find quite an array of bundt cakes.
could this be made in a bundt pan?
Probably!
I made it in a Bundt pan– baked it longer and felt for how jiggly it felt. I waited until it felt very set up, but might have needed yet more time as it was definitely soft in the middle (I have a picture if you want to email me)– you’d want to cover it near the end to keep it from burning as almond flour can so easily do.
Also, you’ll have extra frosting because of not having the middle round layer… or you’ll need to layer it on thicker. I brought the cake to a family gathering un frosted as I had run out of time. While frosting it my father-in-law (type 2 diabetic) couldn’t keep his fingers out of the extra frosting. He was so excited when I told him it was sugar free. It’s excellent on its own and it stays good in the fridge for forever.
I have to tell you a good story—well two stories. The reason I made it in the Bundt pan is my round pounds were in use to make this for a friend’s birthday (her favorite) and it looked so good I made one for me in the Bundt pan. Wow…. we all loved, loved, loved it. So moist and flavorful. I didn’t have the whey so I used egg protein powder as seen in the comments and it was awesome. Even my husband who WILL NOT east zucchini under any circumstances liked it. My friend has been bragging and showing the pictures to everyone and swears her friends who don’t eat low carb would never know.
In fact, her daughter who is usually THE designated/gifted baker in the family was offended I took her place in baking this (her dad commissioned me to make it since she just had baby #3 and is a little busy!). She liked it so much it was part of what made her decide to do keto! She’s going strong now several weeks with great success.
Related—A few months ago that same daughter baked a non-keto, full sugar lemon blueberry cake for a family gathering before her mom (my birthday-friend) was “out of the closet” about being low carb. My friend ate some because she didn’t want to offend her daughter and because she loves lemon blueberry cake so very much. On the way home, the impact of the sugar was so strong her husband was about to pull the car over to see what was wrong… did she need to eat? Did she need a pain pill? What? The hit of white sugar and flour turned her into a NOT-very-nice-AT-ALL-person and she had a terrible sugar crash after that and her MS pain came raging back the next day. It was the last time she’s had sugar and it’s a story she tells everyone that made her the die hard low carb girl she is today. All because of lemon blueberry cake which is now redeemed!
So glad it was a hit with everyone. and your poor friend! Glad she found low carb really helps.