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
- 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
- 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
- ¼ cup fresh blueberries
- 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.
- 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.
- 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.
Can this recipe be used for muffins?
Sure… you will need to experiment a little!
Colleen Prusha says
Another 10 star recipe! I made this as well as the keto chocolate torte on the same day, just for myself and my husband. I bake and portion out desserts to freeze so that we always have a variety on hand for quick dessert. We could not decide which one we liked best! These are right up there with the carrot cake bars which are always in the freezer. I love that there are 16 servings in this cake. The lemon flavor is the best. I did sub lemon flavoring for vanilla and was generous in measuring out the zest. The only thing I would add next time is all of the recommended water to the batter as mine was a bit crumbly. But that frosting! Best frosting, keto or otherwise.
Colleen Prusha says
Oops, forgot to say that I forgot to add the blueberries before dividing dough into pans. I used frozen berries and simply pushed them into the batter a bit and it came out beautifully. I think I may do this every time so that dispersion is more even.
I made this for my son’s birthday. He wanted a blueberry cake. It turned out Great. He loved it.
I absolutely love ALL your recipes. Desserts above all else.
Query – Can I make this case in 13″x9″ pan?
Sure… can’t guide you as to timing since I didn’t make mine that way. Be sure to watch it carefully.
I absolutely LOVED this cake how it was! You cannot even tell it is KETO! I shared with family and friends, one request was a little less lemon! I personally loved the extreme lemon flavor.
Is there a way to take away some of the extreme lemon without ruining the cake itself?
I was looking for blueberry recipes as it is that time of year and I have a lot of blueberries. This recipe is delicious. The cake is extremely lemony which I love! I will definitely be making this again.
Would this recipe work if I cooked them as cupcakes? They’d be easier as cupcakes to take on a family weekend trip we’re taking this coming weekend. If yes, could you give me a guess on minutes to bake? Thanks!
Every cake can be made into cupcakes but you will simply have to keep your eye on them for timing, since I didn’t make mine that way. Start even lower than you think and just keep checking every few minutes.
Made this for Mother’s Day as a desert for myself, loved it!!
So glad you love it!
Donna Williams says
I have made this cake numerous times and it always comes out perfect! Fantastic recipe! Thank you Carolyn!!
Lori Burmeister says
Love this recipe. It is delicious. Is it possible to make ahead and freeze until ready to eat?
I think so but I haven’t tried. In general, I recommend frosting cakes after they’ve been frozen but this one should do fine.
Diane Welch says
I made this cake for a gathering with my whole family, 3 generations. I’m the only one that eats low carb, but we have a lot of gluten issues, so it was perfect. The cake was so darned good! I will make it again, with just a couple of tweaks: 1) I didn’t use powdered Swerve, and the granulated doesn’t dissolve, so the frosting had a little granulated crunch to it, 2) I enjoy the taste of cream cheese, would use more cream cheese and less butter next time in the frosting, 3). Personal choice, I would lessen the sweetener in the frosting and use more lemon zest. All personal choices. 4) it is very soft when finished. We ate it at room temp, but I found it much better textured, held together better, as left over coming out of the fridge, so would put it in the fridge an hour or 2 before serving. The cake as is is amazing! Even The Boy (my daughter’s boyfriend) and my Mom, the 2 pickiest people to please, loved it! Thank you!
Can I use organic chia seed protein powder (I live in the UK) which says to be used as a flour substitute, in place of the protein whey powder?
I am honestly not sure since I have never used chia protein powder. I say you experiment and let me know!