This super fluffy and moist low carb chocolate layer cake tastes as delicious as it looks. With its luscious ganache frosting it makes the perfect keto friendly sugar free birthday cake recipe. You won't believe how easy it is!
Table of contents
You guys, this sugar free cake is incredible! It is so soft and moist, and it has the deepest of deep chocolate flavor!
I made it for my mother-in-law's 87th. She LOVES chocolate and she is a diabetic, so a keto birthday cake was the perfect way to mark the occasion. Happy birthday, Marigold!
It was not until I started eating a low carb diet that I got interested in baking. When there was a birthday, I just bought a cake. They always looked incredible, but even then I used to think they were way too sweet.
After I changed to a sugar free keto diet because of inflammation issues, I started reading labels - and was just shocked at just how BAD those ready-made cakes are for you. The amounts of sugar they contained was just insane!
A sugar free birthday cake
It's actually quite simple to make a sugar-free cake, whether you want to enjoy it for dessert, for a birthday or any other celebration.
All I did is replace the wheat flour with a mix of grain free, gluten-free flours - almond flour and coconut flour. And I replaced the sugar with powdered low carb sweetener.
I swear, you will not taste AT ALL that this cake is sugar free and keto. The reason is that chocolate has such a strong, deep flavour. By making a chocolate ganache instead of a regular sugar free frosting with butter, cocoa and sweetener (especially a vanilla frosting), any aftertaste you may normally detect from the sweetener is just not noticeable.
One thing worth noting is that this is definitely a celebration cake for a more grown-up audience. Unless you have kids who are totally into dark chocolate!
I'm going to post a sugar free vanilla birthday cake with cream cheese frosting soon, so watch that space. I have so many ideas for low carb cakes... it's gonna be a celebration year!
Ingredients
Here are the ingredients! We have all the usual suspects, from blanched almond flour to coconut flour to almond milk, butter, cocoa powder and vanilla extract, baking soda and baking powder to plenty of eggs. (Note - ground almonds / almond meal will work as well).
It may seem like a lot but don't forget we are essentially making a layer cake with two sponge cakes, which we stack on top of another.
The secret ingredient for fabulous fluffiness
The secret ingredient that makes this recipe extra fluffy without the need to whisk the egg whites separately is - yoghurt! It is just AMAZING for getting that rise we all want in a really good gluten free cake.
How to make a low carb chocolate layer cake
(This section contains step by step instructions and photos that show how to make this recipe. Find the recipe card with ingredient amounts and nutritional information at the bottom of the post.)
Sugar free chocolate sponge
Add all ingredients to blender and blend until smooth. You may need to scrape the sides a couple of times and blitz again.
Tip: By adding the wet ingredients FIRST and the dry ingredients SECOND, you avoid the flours sticking to the bottom.
Also, don't forget the salt. It adds depth of flavor to the recipe.
You may need to scrape the sides a couple of times and blitz again.
Note: If you don't have a blender, use a large bowl and an electric mixer.
Pour batter into two generously greased non stick baking tins (I used butter to grease the sides).
You can also line the sides with baking paper if you worry about the batter sticking!
Bake in the oven for about 35 minutes or until you can insert and remove a toothpick without any crumbs sticking.
Do not over-bake as the sponge will firm up as it cools.
Low carb chocolate ganache
Now on to the sugar free frosting! I decided on a rich ganache instead of a chocolate buttercream frosting, because when you're making a grown-up cake, you may as well pull out all the stops.
Basically, you warm the heavy whipping cream in a pan and heat it, but do not boil.
Then, turn off the heat and add finely chopped dark chocolate (85% cocoa solids minimum, or 90% as it's very low sugar) or sugar free chocolate chips such as Lily's to the cream.
DO NOT STIR! This can cause the mix to split, because it cools down too quickly. First, let the mixture sit for 5 minutes.
Then, stir with a spatula until the chocolate is fully melted and combined with the cream.
Flavor tweak: add 1 teaspoon of orange extract and the zest of 1 orange or 1 tablespoon of peanut butter to the ganache.
Tip: If your ganache does split, don’t panic! Just put in a food processor and blend until smooth and it will right itself.
As soon as the the chocolate frosting has cooled a little so it's not boiling but still easily spreadable, spread it over both (fully cooled) cakes.
Wait until the ganache has set, then stack the cakes on top of one another to make one gorgeous sugar free birthday cake!
You could serve it with whipped cream or a scoop of ice cream, but I just added some grated chocolate on top and a few red currants.
Substitutions for this sugar free birthday cake
I always get questions about how to substitute ingredients, because of intolerances or simply dislikes. Here we go!
Can I use just almond flour?
You can replace the coconut flour with an additional 1 ¼ cup or 125g of almond flour (use only 1 cup if your almond flour is super fine).
Can I just use coconut flour?
No. This is not the ideal recipe to experiment with this because of the amount and cost of ingredients.
As a rule of thumb, I would use â…“ the amount of coconut flour stated for almond flour - about 80 grams / a scant â…” cup. But I think you would also need to add about 2 additional eggs to achieve the same fluffiness.
If you decide to try, let me know how it went!
Other sugar free sweetener options
Yes! I used a powdered erythritol / monk fruit sweetener mix. But allulose or xylitol will work equally well. I like natural sweeteners - no sucralose, no maltitol, no artificial flavor.
Powdered sweetener does work best, because it will give a smoother texture. If you only have granulated sweetener, simply blend it first in the food processor to powder it.
How to make this cake dairy free
It's easy to create a dairy-free version of this diabetic birthday cake. Just replace the butter with coconut oil and the yoghurt with coconut yoghurt.
The ganache works equally well if you replace the heavy cream with coconut cream.
Cake pan sizes
I used two 8-inch cake pans. 9-inch rounds also work, just note that the cake will be flatter.
You can use a rectangular cake pan or even a bundt pan to make one large cake. The baking time will increase to around 60-70 minutes, depending on the pan size.
It's also possible to make cupcakes with the batter. Baking time will be around 25-30 minutes.
Storage
This cake tastes best at room temperature, because then the ganache is lovely and soft.
I would, however, store it in the fridge. It will stay fresh for up to 4 days.
How to freeze chocolate ganache cake
This cake freezes really well. There are two different methods:
Freezing the sponge separately
If you know that you are making the cake ahead you can freeze the two chocolate sponge cakes separately and make the frosting after you defrost them.
Freezing the entire cake
I you freeze cake low carb birthday cake leftovers, I recommend that you make enough room in the freezer to freeze the cake on a plate. Only after it is fully frozen, carefully place it in freezer bags or containers. This way, the ganache won't be damaged.
Freeze for up to 3 months.
Making a small low carb birthday cake
Last but not least - if you don't want to make a HUGE cake, simply halve the recipe and make a single layer of sugar free cake topped with ganache.
All ingredients can be halved easily - except for the 7 eggs. I recommend that instead of large eggs, simply use 4 medium eggs.
More chocolate keto cake recipes
Keto Chocolate Lava Cake - Best served warm, this low carb keto cake has wonderfully gooey centre. My readers love it.
Best Ever Keto Chocolate Cake (Sugar Free) - the most popular keto cake recipe on the website. It is dense and fudgy and it contains only 5 ingredients.
Easy Keto Triple Chocolate Mug Cake - Great if you are after a chocolate quick fix. This is a coconut flour recipe and it is just so fluffy and light, but with amazing deep chocolate flavour.
Keto Double Chocolate Cheesecake - A showstopper recipe if you've got a big crowd coming over. My guests always adore it, whether they are low carb or not!
Tried this recipe? Give it a star rating below!
★ STAY IN TOUCH on FACEBOOK, PINTEREST and INSTAGRAM for more great food and join my NEWSLETTER for the latest updates and a FREE EBOOK.★
Low Carb Sugar Free Chocolate Birthday Cake
from Sugar Free LondonerNote: The servings slider only changes the first amount in each line and not any subsequent amounts. Please make your own calculations where necessary. ***As an Amazon Associate I earn from qualifying purchases.
Ingredients
Chocolate Sponge
- 7 large eggs
- â…“ cup / 84g Greek yoghurt
- 2 teaspoon vanilla extract
- â…” cup / 170g almond milk
- 3.5 oz / 100g butter melted
- â…“ cup / 45g coconut flour
- 2.5 cups / 250g almond flour
- 1 cup / 90g cacao powder
- 1 ¼ cup / 200g powdered sweetener
- 3 teaspoon baking powder
- 2 teaspoon bicarbonate of soda
- â…“ teaspoon salt
Chocolate Ganache
- 1 cup plus 2 tablespoon / 200g sugar free chocolate chips or 85 - 90% dark chocolate roughly chopped
- 1 cup/ 240ml heavy cream
Instructions
Chocolate Sponge
- Preheat the oven to 180C / 350 Fahrenheit. Generously grease two 21 x 4 cm round non-stick baking tins with butter.
- Add all ingredients to blender, starting with the wet, and blend until smooth. You may need to scrape the sides a couple of times and blitz again.
- Spoon the mix into your greased baking tins and bake for about 35 minutes or until you can insert and remove a skewer without any crumbs sticking. Do not over bake as it will firm up as it cools.
- Allow to fully cool.
Ganache
- Place the cream in a pan on med/ low and heat until hot, just as it starts to simmer. Do not boil. Turn off the heat.
- Chop the chocolate quite fine. Add to the hot cream. Do not stir. Let the mixture sit for 5 minutes. Stirring will cool down the mix too quickly and may result in splitting.
- Stir with a spatula until melted. If your ganache splits, don’t panic, just put in a food processor and blend until smooth and it will right itself. Allow to cool for a couple of minutes so not boiling but still easily spreadable.
Assembly
- Spread the ganache on the top of both cakes. Allow to set and then stack the cakes one on top of the other.
Video
Notes
Nutrition
This post contains affiliate links. If you click on one of these links and purchase a product, I may earn a small commission, at no extra cost to you. Thank you for supporting Sugar Free Londoner.
Sarah
Hi! I'm thinking of making this cake for my mother's birthday. She's diabetic but very opposed to sweeteners and prefers, if she is going to have something sweet, to have real sugar but just not too much of it. Could I substitute the powdered sweeter with say half the weight in caster sugar or could this affect the texture of the cake? Understand it may not be as sweet but I think that would be more to her taste anyway.
Thank you!
Katrin Nürnberger
Yes, that should work fine.
Rachelle
Hi, I was wondering if gluten-free all-purpose flour can be used in this recipe.
Katrin Nürnberger
I have not tried that yet. I assume you would need a similar amount - perhaps a little less because it is ground more finely.
Amna
Definitely my favorite one.
Can I add flavors such as raspberry?
If I add fresh raspberry to the Ganache?
Katrin Nürnberger
Yes, raspberry and chocolate always go well together. You could top the cake with freeze-dried raspberries, or add freeze-dried raspberries to the ganache. You could also add a layer of my raspberry jam.
Marie
My new favorite chocolate cake!! I only made the cake, not the ganache and it’s an instant hit. Thank you @sugarfreelondoner! These ingredients are always in my kitchen though results this good are few & far between lol. I love how great it turned out.
Lydia
My husband is newly diabetic but my son has a nut allergy- is there an alternative to almond flour & milk?
Katrin Nürnberger
You can use coconut milk or any other milk instead of the almond milk. I cover substitutions in the post. Normally, a blend of sunflower seed flour and sesame seed flour works well in place of almond flour. I also have a recipe for coconut flour chocolate cupcakes you can use instead.
Marianne
Hi, I'm making your delicious looking cake today. I'm wondering if monk fruit with erythritol converts the same to the 200g sweetener powder called for in the recipe?
Katrin Nürnberger
It should do. Make sure your brand is a 1:1 sugar alternative. Some sweeteners are twice as sweet as sugar, in which case you would need half the amount.
Brigitte
I made this cake for my sister who was celebrating her 50th birthday. She has recently moved to a sugar/gluten free lifestyle. I followed the recipe exactly….other than I baked 30 minutes, I have a convection oven. It turned out beautifully rich but not sweet. I have baked a few low carb no sugar items from other sites and haven’t had the greatest luck. I was really impressed with how easy and the end result. I would recommend this cake to anyone looking for a decadent dessert!
Toni
Made this cake for a family birthday party & it was a hit! Making another one today for my sister's birthday. I did make it dairy free & used a different frosting recipe. Think I might try to ganache today. Thanks for the great recipe!
Isabella
Hey! I wanted to make this for my coworker who can't have sugar, so I don't need it to be gluten free or keto, just sugar free.
Could I use all purpose flour instead of almond and coconut?
And can I use milk instead of almond milk?
Thanks 🙂
Katrin Nürnberger
You can use any milk you like. However, I do not recommend to switch the flours. This recipe is designed for them and you may need different amounts if you swap. Also, you're doing your colleague a favour - white flour is converted into glucose by our bodies, which will spike insulin levels. Hope you'll all enjoy the cake!
Sarag
Can I use a kitchen aid mixer ? Will it be different in terms on how to mix everything
Katrin Nürnberger
Yes, of course. Any electric mixer works for this recipe.
Jan
Made this for my grandson's birthday cake. It was easy to make and delicious served with some unsweetened cream. Thank you for the recipe
Toni
So is "bicarbonate of soda" simply baking soda?
Katrin Nürnberger
Yes, that's correct.
Jane
Hi, can I do this with liquid stevia somehow?
Thanks!
Katrin Nürnberger
It should work, yes. You'd have to calculate how much stevia you'd need to use. 4-5 drops is normally equivalent to 1 teaspoon of sugar. And 3 teaspoons is 1 tablespoon. 4 tablespoons are 1/4 cup. Check whether you need to use a little more almond flour to make up for the missing sweetener granules (=dry ingredients).
Sue
Hi, making this for a colleague, it’s a big team so I’m doubling the recipe, what size cake tin should I use please?
Many thanks
Katrin Nürnberger
Hi Sue, I'm not sure! This is already a pretty large cake. You'd have to do the maths... I'm guessing you'd use a rectangular cake tin? This would alter the baking time as well.
Ellie
Hello. How many cups or tablespoons is "100 grams" of melted butter? I don't understand Oz and grams
Katrin Nürnberger
100g of butter is 1/4 cup plus 3 tbsp
nav
Hi,
How can I make this cake vegan please?
nav
Katrin Nürnberger
There's a lot of eggs in this recipe, which means you'd have to completely re-write it to make vegan.Sorry I cannot help with this one!
Yasemin
Can I bake the cake in 1 pan at once and cut it in half?
Katrin Nürnberger
Yes of course. You'll have to increase the baking time though to ensure it's not sticky in the middle. It will most likely take 55-60 minutes. Also, cover the top loosely with aluminium foil after about 35 minutes to ensure the top does not over-brown.
Izzy
Heya, I want to make this for my grandad who is diabetic. Could I use any sort of fruit as a sweetener like apples please
Katrin Nürnberger
Hi Izzy, using apple instead of the sweetener would change the texture of the cake since you are adding more moisture. Therefore, you would have to change the amount of wet ingredients as well. I also think that using just apples to sweeten may not be enough sweetness.
Katherine Fite
my cakes sunk in on themselves. is this normal, or was my pan too small or something? I used two 10-inch pans.
Katrin Nürnberger
Reasons for cake sinking could be 1. out of date baking powder 2. cold ingredients, which would cause the inside of the cake to bake longer.
Ton
In the article, she said she used 8 inch pans, but 9 in would work, the cakes would just be flatter. 10 inch is definitely too large.
SARAH
I am going to try this dairy free. Replace dairy yogurt with almond milk yogurt, non dairy butter and coconut cream. Should work out just fine.
Sarah
I wanted to update. I did the recipe dairy free and since I don't have a blender or food processor I used my Kitchen aide mixer. I came out spectacularly well. My chocolate lovers were over the moon with chocolate goodness.
Diane
Would non-dairy coconut yoghurt work with THIS? I think I'm going to try it since I'm dairy free, gluten and sugar free, It's a real challenge.
Katrin Nürnberger
Yes, I think that would work.
M Nel
My chocolate chips did not melt, I tried everything. Any other alternatives for a delicious chocolate 'frosting' that lasts a few days?
Katrin Nürnberger
I would just use a quality dark chocolate then - like the 90% Lindt, for example. It melts like a dream.
Jacquie
What size cake tins please. Looking forward to trying this.
Thank you,
Katrin Nürnberger
They were 20 cm diameter.
gerlie
Hi can I bake it using an air fryer? Because I don't have an oven and I want to bake a sugar-free cake for my mom.
Katrin Nürnberger
I have never tried baking cakes in the air fryer, but I do use it a lot for savoury recipes. It should work! From my experience, things cook faster in the air fryer, so I'd keep that in mind and start checking a little earlier whether the inside is done and to make sure the top does not burn.
gerlie
Hi! It worked and it turned out great! Thanks for sharing this recipie!
Toni
Although I love chocolate, I would like it to be less dark. If I adjust the cocoa powder to 2/3 cup, would I also need to decrease the almond milk a bit?
Katrin Nürnberger
Yes, that's what I would do.
Kathy
Best keto chocolate cake recipe. Thank you!
Katrin Nürnberger
So glad you like the cake!
Olena
Delicious!