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.
Beth says
Wondering if I can use frozen blueberries? Can’t wait to try this.
Carolyn says
Sure… just know that frozen blueberries tend to bleed a lot more into the batter when you stir them in.
Melissa K says
Thank you once again Carolyn for a delicious cake!!! Love that there is zucchini “hidden” in there for non-vegetable eaters!! 🙂
Diane says
What is the baking time for cupcakes? Can I freeze them?
Carolyn says
I don’t know the timing, you will simply need to watch them carefully. You can freeze them without the frosting.
Lorraine says
Blueberry and lemon = wonderful match! Since a whole cake is too much for only one person, can it be frozen in quarters without the frosting?
Fern Greenspoon says
I’m not a fan of icing. Can I make this in a loaf pan? Hav you tried this? Any suggestions for oven temp and bake time?
Thanks
Carolyn says
No, I have not tried it. I think you will need to experiment but most loaf cakes take at least 45 to 50 minutes to bake through.
Nikki says
I have used this recipe for many birthday cakes with so much success! Thank you for this delicious and healthy recipe.
George says
Made this for my birthday. Had a social distancing party with neighbors and they all were asking what the heck made this cake Keto cause it was so good. Easy to make. Great flavor. Thank for making my birthday gathering a hit with this recipe.
Carolyn says
So great to hear!
Marilyn Curtis says
This cake Is not delicious . I really can’t serve it. The texture was gritty from the almond and coconut flours I guess. It didn’t rise very much but that wasn’t the problem. Sorry can’t say it was wonderful. Guess it was for everyone one else.
Carolyn says
Please tell me what brands of almond and coconut flour you used. Because the cake, made properly, is not at all gritty, and it rises quite nicely.
Wendy says
Recipe says “1 medium zucchini (@200g)“. 200g is a little less than 1 cup. My medium zucchini shredded yielded 2 cups shredded. Do I use 2 cups shredded or 1 cup?
Carolyn says
Cups are not a great measurement for something like grated zucchini, since packing it can make a huge difference to the weight in the cup. So your equivalency of “200g is a little less than a cup” is not at all accurate here. That equivalency is more for items like flour and sugar.
But if you got 2 cups and you didn’t pack it hard into the cup, then go with that. Once it’s squeezed and drained, then it becomes more like a cup, hard-packed.
Amanda says
Made this for my husband’s birthday. We LOVED it. Some keto baking is bland, but not this one, tons of lemon flavour and moist but light cake. Another win!
Carolyn says
So glad to hear it!
Jen says
This cake was so delicious and the lemon frosting add a great touch to the overall flavor. Love that I have another option for all of the zucchini growing in my garden.
Anna says
This cake is a perfect summer dessert! I love the blueberry and zucchini combo!
Eden says
This is so good! Very flavorful and moist!!
Veronica says
I only had one pan, and I was too lazy to bake 2 layers separately, so I risked it and made one. I was hoping to cut it, but quickly realized that wouldn’t work, so I poked holes all around it and poured all the frosting on top. For some reason the frosting turned out very liquid ( I guess I softened the butter and cream cheese too much), so everything sort of went wrong 😀 And nonetheless, it turned out absolutely delicious. I think it’s one of my favorite recipes so far, and I tried – and loved! – at least a couple of dozen of yours. Next time I will try making the same amount of ingredients, but bake it in a smaller pan. If the cake is higher, I think it might be possible to cut it in two. Just wanted to share my experience.
Thanks a lot for another great recipe!
Jennifer Ward says
What’s the sugar content in this recipe?
Carolyn says
I don’t calculate that because I think it’s irrelevant (carbs are the important piece here and since sugars are carbs, it’s not going to be more than the carb count) but you are welcome to calculate it yourself using any number of online resources.
Keylee says
Can you use collagen peptides in place of whey protein powder?
Carolyn says
Nope! Don’t do it! The only good replacement is egg white protein. collagen makes baked goods gummy.
Simone Ribanic says
I made this today and it smells absolutely delishes! I followed the recipe to the T but for some reason the batter did not rise. Not sure where I went wrong. Cant wait to cut into it
Carolyn says
I wonder if your baking powder is old? Keto cakes don’t rise as much as conventional ones but they should rise some.
Kayla says
I plan on making this Tueaday, but I couldn’t find unflavored protein powder, so I got smooth vanilla… do you think it will make a big difference? Thanks.
Carolyn says
Often those protein powder flavours can be a bit strong. You may get more vanilla flavour so add a touch more lemon if you can to offset it.
Gio says
That looks delicious. I’m wondering. Can I substitute the wey protein powder for batted egg whites? If so, how many? TIA
Carolyn says
No, only egg white protein powder can replace the whey.
Jen says
I don’t have whey protein but i do have pea protein powder. Organic protein powder. Is that ok to use instead?
Carolyn says
I hope so but some pea protein is greenish in colour…