Celebrate summer’s bounty with this delicious Keto Blueberry Zucchini Cake with Lemon Frosting. It brings so many delicious flavors together in one sugar-free dessert!
I first created this delicious keto lemon blueberry layer cake in the summer of 2015. It’s such a summertime classic, I decided it needed an update. It now has the same great flavor and is even lower in carbs.
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 no-bake 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 layer 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!
Remaking Keto Blueberry Zucchini Cake
This cake has long been one of my favorites because it brings together so many wonderful summer flavors. I am usually a diehard chocolate cake girl, but the light tangy sweetness of this Lemon Zucchini Cake, bursting with blueberries, won me over right away. The original was inspired by a cake I saw on I Am Baker.
But my first version of this recipe was a bit higher in carbs than I like to eat now, and my original photos were a bit overexposed. So it was time to tackle it again and see if I could make it even healthier.
Are blueberries keto?
The reality is that any food can be “keto” if you eat small enough amounts of it.
But it turns blueberries, while super healthy and full of antioxidants, are actually not the most keto friendly fruit. While 1 cup of raspberries has 15g of carbs and 8g of fiber, 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.
So 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 subbed out some of the almond flour for a little coconut flour, and cut back on the sweetener in both the cake and the frosting.
Tips for making Lemon Blueberry Cake
This is a delicious keto cake for summer, and it’s really not that hard to make. Here are my best tips for getting it right:
- Squeeze the zucchini very dry. 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 up. I don’t like to have to clean a tea towel, so I just do it with my hands.
- Mix up your dry ingredients first, before beating the butter, so that it’s ready to add in as needed. And yes…the protein powder is critical to the recipe. It helps the cake rise better. The only good substitute is egg white protein powder.
- Make sure your butter is well 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.
- This goes for the frosting too! Make sure both your cream cheese and butter are well softened so they beat smoothly. Who wants clumps of cream cheese in their frosting?
- 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.
Ready to make some delicious Keto Lemon Blueberry Zucchini Cake?
More Delicious Keto Blueberry Recipes
- Keto Blueberry Muffins
- Keto Blueberry Upside Down Cake
- Keto Blueberry Pancake Bites
- Lemon Blueberry Scones
- Keto Lemon Blueberry Donuts
- Blueberry Cheesecake Squares
Keto Lemon Blueberry Zucchini Cake
Ingredients
Cake:
- 1 medium zucchini shredded (about 200g)
- ¼ teaspoon salt
- 2 cups almond flour
- ⅓ cup coconut flour
- ⅓ cup unflavoured whey protein powder
- 1 tablespoon baking powder
- ¼ teaspoon salt
- ½ cup butter softened
- ¾ cup Swerve Sweetener
- 3 large eggs room temperature
- 1 tablespoon lemon zest
- ½ teaspoon vanilla extract (try lemon extract for more lemon flavor!)
- ¼ cup freshly squeezed lemon juice
- ¾ cup blueberries fresh or frozen
Lemon Frosting:
- 8 ounces cream cheese softened
- ½ cup butter softened
- 1 cup powdered Swerve Sweetener
- 2 tablespoon freshly grated lemon zest
- ¼ cup freshly squeezed lemon juice
- 2 tablespoon heavy whipping cream
Garnish:
- ¼ cup fresh blueberries
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 325F and grease 2 (two) 9-inch round cake pans very well. If your pans are not very non-stick, you may want to line them with parchment paper and grease the parchment.
- In a medium bowl, combine the almond flour, coconut flour, whey protein, 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 tablespoon 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.
To Assemble:
- Place one cake layer on a serving platter and spread the top with half of the frosting. Add the second cake layer and spread with the remaining frosting. Top with fresh blueberries.
Claire says
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!!!!!!
Meghan says
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!
Meghan says
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!!
Stalacea says
Do you use green zucchini or yellow squash?
Carolyn says
Green zucchini.
Andrea says
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!!!
Carolyn says
Sure, it’s basically the same.
Jan says
Does this taste like zucchini? I like zucchini, but maybe not a cake that tastes like it.
Carolyn says
No, zucchini simply adds moisture to a cake like this.
Gloria says
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!
Carolyn says
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.
sonya says
Thanks… Do you have any bundt cakes other than the Buckeye?
Carolyn says
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.
sonya says
could this be made in a bundt pan?
Carolyn says
Probably!
Sheena McKinney says
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!
Carolyn says
So glad it was a hit with everyone. and your poor friend! Glad she found low carb really helps.
Kyme says
Could I replace the whey protein powder with a TBS of homemade baking soda?
Carolyn says
I am doubtful that would replace the whey properly but you are certainly welcome to try.
Cheryl says
Made this tonight and it is out of this world fantastic! What a perfect delicious cake! This is so very flavorful, light and airy and a perfect combination. My husband and I both agree its one of our favorites! Thank you so very much!
Shelby says
I’ve got this cake in the oven now and it smells incredible! I used coconut flour instead if almond flour and I had to add quite a bit of unsweetened almond milk for it to even be spreadable. It seems really dense. I really hope it turns out okay! I can’t wait to try it!
Carolyn says
You can’t replace almond flour with coconut flour without increasing the eggs significantly. Please see my tutorials on working with coconut flour and almond flour. https://alldayidreamaboutfood.com/2013/04/low-carb-basics-baking-with-coconut-flour.html And https://alldayidreamaboutfood.com/2013/02/low-carb-basics-baking-with-almond-flour.html
Linda Lauritzen says
I can hardly wait to try this recipe! I love lemon and blueberry together!
Tami says
This looks absolutely fabulous and I can’t wait to try it! I don’t have any Swerve. Can I substitute THM Sweet Blend? If so, how much?
Elissa says
Yummmy! is what I have to say. I made this scrumptious cake yesterday and it is delicious. I was worried that it was going to be dry because of how it looked coming out of the oven and I wasn’t sure if you measured the zucchini before or after squeezing it out. My worrying was in vain, we loved it and it is super moist. I went lighter on the sweetener because I’ve gotten used to things not too sweet, next time I will use even less.
Lorri says
This is a delicious recipe. I have made it twice now. The cake is light and delicious. Just a couple of thoughts. First, for my family this icing is way too sweet. I’m wondering if 1-1/4 cup of serve is accurate. I have found that Swerve is so sweet, I can usually cut it by half. For my second time making this, we actually used half the amount of sweetener for the icing, and a little less than 1 cup for the cake. It was perfect, for my family, this way. Second, for my second try at this, I wanted to use Xylitol and Swerve because I noticed the cooling effect the first time I made this recipe. This is just a preference. To add the Xylitol to icing, I melted the butter and dissolved it, otherwise the Xylitol would have had a grainy texture in the icing. It turned out perfect this way. Finally, I used “lemon extract” in this recipe and that also worked well. Your recipes are always delicious and I thank you for sharing them with me and my family.
Carolyn says
Thanks for your thoughts, Lorri. Everyone differs in terms of taste and sweet tooth(s). Many readers find my recipes not sweet enough so I always try to find a middle ground. 🙂 But you may be a super taster of things like erythritol so use what works best for you.
Lorri says
Thanks again Carolyn. I’m going to try your “Victoria Sponge Cake” recipe next. 🙂
LizD says
This cake is beautiful and absolutely delicious! We just finished eating our sample slices. Hubs, who has no need to watch his carbs and doesn’t like zucchini, gobbled his right up.
This will be a special occasion cake in the future. Yum!
Wendy says
Should the zucchini be rinsed before draining?
Carolyn says
No need.
Leslie says
You have salt listed twice in the recipe. I’m sure it’s an error, yes?
Carolyn says
No, that’s not an error. You salt the zucchini before you drain it and you also add a touch more salt to the batter.
Alyssa (EverydayMaven) says
This looks sooooo good Carolyn – I wish I had a slice right now. And, I have definitely had that experience of meeting someone in person and thinking they got switched with their online personality!
Maytha Kilgore says
Sounds good. I don’t have Swerve, okay to substitute either Truvia or Splenda?
Carolyn says
Truvia would be fine in the cake part but you really need a powdered sweetener for the frosting. Plus Truvia is sweeter than Swerve and doesn’t measure like sugar so I am uncertain of the amounts.