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)
- 1/4 tsp salt
- 2 cups almond flour
- 1/3 cup coconut flour
- 1/3 cup unflavoured whey protein powder
- 1 tbsp baking powder
- 1/4 tsp salt
- 1/2 cup butter, softened
- 3/4 cup Swerve Sweetener
- 3 large eggs, room temperature
- 1 tbsp lemon zest
- 1/2 tsp vanilla extract, (try lemon extract for more lemon flavor!)
- 1/4 cup freshly squeezed lemon juice
- 3/4 cup blueberries, fresh or frozen
Lemon Frosting:
- 8 ounces cream cheese, softened
- 1/2 cup butter, softened
- 1 cup powdered Swerve Sweetener
- 2 tbsp freshly grated lemon zest
- 1/4 cup freshly squeezed lemon juice
- 2 tbsp heavy whipping cream
Garnish:
- 1/4 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 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.
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.
Nutrition
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Lemon and blueberry is one of my favorite combinations!
Always a great flavor combo!!
This is one of my favorite low carb recipes. I’ve made both this and the regular version together for a pot luck and had more people like the low carb version! I can hardly wait until next zucchini season.
This looks yummy! A couple of questions:
1. If I use a 9X13 pan, how should I adjust cooking time/temp?
2. If I use a “Gluten Free Flax & Ancient Grains All-Purpose Flour,” (brown rice, flaxseed, quinoa, buckwheat, and amaranth) should I use the same amount as the almond flour? Would I still need to add a protein powder.
Thanks for the great recipe!
I am sorry, I cannot guide you using the flour you suggest as I don’t use anything like that.
This is my new favorite ands I’m out of almond flour!!! Any chance I can use coconut flour if I don’t drain the zucchini as well?!? Thanks in advance!
You’d really need to change the recipe entirely. You could try using this recipe but don’t use vanilla bean and cut way back on the other liquid until you know how much moisture the zucchini adds. https://alldayidreamaboutfood.com/2017/08/keto-slow-cooker-bacon-cheeseburger-pie.html
Hi Carolyn
I really enjoy reading your recipes but can not bring myself to use all the artificial sweeteners and so much of it. Have you tried using date purée or coconut butter or even prune purée?
Thank
Scott Belanger
HI Scott, I don’t use any artificial sweeteners. Erythritol is a naturally occurring substance, as is stevia and monk fruit. So no worries there! However date or prune puree is not a possibility for me, with diabetes. And to be frank, it’s essentially sugar in another form.
This was sooooooo good Carolyn!!! Thank YOU so much and as always I am loving every bite! Was hoping my husband would not like it so there would be more for me…but he loved it too!
Thanks again!
Do you have a suggestion for a dairy free frosting for this cake? thanks!
The only decent low carb dairy-free cream cheese I have ever tried is Kite Hill. I found it at Whole Foods.
Not to ask the same question again, but I dont use protein pwders..should I add more almond flour or some coconut flour instead and then another egg or more butter as suggested previously?
Sure.
Hi! This looks great–two questions–is the zucchini measured before or after draining, and should it be packed? Thanks!
Measure before draining and don’t pack.
Do you think I could make this in a loaf pan? …or would the middle not ever get done before the outside turned into leather, lol?
I think it may get brown on the outside but it should end up okay. Cover with foil while baking to keep it from being too brown.
OH MY GOODNESS… I made this cake and it was moist, and so delicious.. AND, it did virtually nothing to my blood sugars.. I used vanilla protein powder and added a bit of lemon extract to both the cake and the frosting. .I will be making this cake all the time.. Thank you for all your hard work and recipes. I cant wait to receive your new book.
HI! Would it work if I subbed THM baking blend for the almond flour?
Thanks, can’t wait to try this. Love your recipes!
Baking blend tends to be much drier so you may find you need a little more butter or another egg.
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.