This 5 ingredient keto chocolate cake is the pinnacle of sugar free desserts! It is incredibly moist, rich and packed with chocolate flavor. Even better, it has only 2.5 net carbs per slice.
Do you want to see everyone at your table sink into silence, occasionally interrupted by a contented sigh? Serve this low carb chocolate cake and watch the magic happen.
Table of contents
- Low carb chocolate cake essentials
- How to make Keto chocolate cake
- Recipe tips
- Flavour and Recipe Variations
- Toppings for this keto cake
- Make a layer cake
- More decadent keto desserts with chocolate
I love all the recipes I post on this site, but this recipe is special. That's because it's more than just a chocolate cake. It's a crazy good, wonderfully rich Keto chocolate cake.
This Keto cake does nothing by halves. It contains as much chocolate as it can possibly handle, a generous amount of grass-fed butter and it is just on the right side of sweet. Basically, it is a Keto dream dessert.
It will satisfy the cravings of any chocolate lover. And it also makes a great gluten-free birthday cake!
Low carb chocolate cake essentials
There are 2 ingredients that increase carbs and sugar in a traditional cake: the wheat flour and, of course, the sugar.
As grains are a no-no on a Keto diet (as well as on a sugar free / low carb diet), most Keto cake recipes use either almond flour or coconut flour or both. This cake uses only a very small amount of almond flour, which makes it super fudgy, almost like a brownie.
And of course, I'm using a sugar substitute in place of sugar. For this cake, I've chosen an erythritol/stevia blend. Erythritol is a polyol and cannot be absorbed by our body. Therefore, it's essentially zero carb and does not raise blood sugars.
You can replace the erythritol in this recipe with xylitol, monk fruit sweetener, allulose or with Splenda. If you're using Splenda, be sure to measure using cups as it's lighter in weight than erythritol. And if you're using xylitol, keep it away from dogs. It's highly toxic to them!
It's hard to believe, but you only need 5 ingredients to make this cake:
- Unsweetened chocolate
- Almond flour
...and a pinch of salt.
Shall we get straight to the recipe?
How to make Keto chocolate 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.)
1.) Whisk the eggs with a hand mixer in a large mixing bowl until they have doubled in size and are frothy.
You want to make sure that the eggs are ROOM TEMPERATURE. If you forgot to take them our 30 minutes before starting on the cake, you can always warm them up in a bowl with hot water.
Keeping the eggs at room temperature prevents the mix from splitting and becoming lumpy once you add the warm chocolate and butter.
2.) Add the powdered erythritol and whisk again until well-combined.
Tip: If you only have granulated sweetener, blitz it in a food processor or with the attachment of a stick blender to turn it into a powder. You don't want any crunchy bits in your gooey, moist chocolate cake!
TASTE the cake batter and add more sweetener if necessary. I don't have much of a sweet tooth, so you may prefer it a little sweeter than I do.
3.) Melt butter and chocolate and stir until combined. You can do this in a microwave or on the stove - but slowly and gently. TAKE YOUR TIME!!! If the chocolate gets too hot too quickly, it can seize or separate.
Then add the mix to the bowl and fold it in with a spatula or spoon.
4.) See how it's slowly coming together?
5. And this is how it should look like - gooey, creamy goodness!
6.) Lastly, you add the almond flour / ground almonds and stir until they are evenly distributed.
7.) Get yourself a springform pan (I used a 20 cm / 8 inch) and line the bottom with parchment paper. Grease the sides with butter or oil and pour in the batter. Bake at 170 Celsius / 340 Fahrenheit on the middle shelf for 30 minutes.
Let the cake cool completely before cutting.
One thing I absolutely love about this low carb chocolate cake (apart from the taste!) is the fact that the recipe contains only 5 basic ingredients.
This also means that these ingredients MUST be the best possible quality, especially the chocolate.
Best chocolate to use
Here in the UK there are a range of artisan chocolate makers which produce unsweetened chocolate. The brand I used, Montezuma's, is available at Sainsbury's, in organic shops or online. In the US you can go for a brand like Ghirardelli.
I don't recommend choosing unsweetened Baker's chocolate for this cake. It has the tendency to seize when you melt it and simply does not taste as creamy and mellow as quality chocolate.
The right way to melt chocolate
Which brings me to my second recommendation: Take your time melting the chocolate!
When you melt the butter and chocolate in the microwave, do so in 30 second bursts. Mine was mostly melted after 90 seconds in total. I then left the bowl on the kitchen counter and stirred it from time to time. This caused the rest of the chocolate to melt slowly.
If you don't have a microwave, you can melt chocolate in a water bath. For this, you either place the bowl with your chocolate and butter in a heat proof bowl over a pot with boiling water. Once the chocolate is half-melted, remove the bowl and let it fully melt by stirring occasionally.
Baking at high altitude
If you are baking at high altitude, increase the oven temperature by 10 Celsius / 25 Fahrenheit.
Flavour and Recipe Variations
SPICE IT UP: I think all chocolate desserts benefit from a pinch of salt, although this is entirely optional.
To give your keto cake a festive vibe, you could add 1 teaspoon vanilla extract, 1 tsp cinnamon plus some cardamom, nutmeg and a pinch of cloves.
For an extra kick, try adding a pinch of chilli! Or grate the zest of 1 orange into the batter.
MAKE IT NUTTY: Add nuts for a bit or crunch - walnuts or pecans would work well.
FLUFFY TEXTURE: This cake is supposed to be fudgy. For a slightly fluffier texture, you could add 1 teaspoon of baking powder or ½ teaspoon of baking soda.
I don't recommend to replace the chocolate with cocoa powder.
DAIRY-FREE: Replace the butter with coconut oil.
NUT-FREE: Use ¼ cup coconut flour in place of the almond flour.
Toppings for this keto cake
I'm a bit of a purist, so I simply dusted my cake with 100% unsweetened cocoa powder and served on a pretty cake stand.
You could also dust the low carb cake with powdered sweeter.
If you want to go the whole nine yards, make a cream cheese frosting or a buttercream frosting.
Or how about a quick chocolate ganache? Melt 1 bar (100g) of chocolate and stirring in 3 tablespoon of double / heavy cream and 4 tablespoon powdered sweetener.
You could serve this cake with a dollop of whipped cream or a scoop of sugar free vanilla ice cream.
Keto chocolate frosting
- Melt 100g / 3.5 oz unsweetened chocolate and 60g / ¼ cup butter
- Stir in 6 tablespoon heavy cream and ⅓ cup / 50g powdered sweetener
- Wait until the mixture has cooled and thickened, then spread over the cake or slice it horizontally and fill in between the layers.
Make a layer cake
To make a layer cake, either slice the cake in half or split the batter between 2 cake pans. The baking time should be about 25 minutes, but do check after 20 minutes and see if it needs any longer.
Let the layers cool completely, then add the keto chocolate frosting as described above.
Which cake pan to use
I used a 20 cm / 8 inch springform in this recipe. If you only have a standard size 25 cm / 9 inch springform, your chocolate keto cake will be a little flatter, but it still works fine. You may need to reduce the baking time by 5 minutes. Simply check after 25 minutes if the middle of the cake feels firm to the touch.
Store this sugar free cake in the fridge for 5-6 days. Be sure to keep it in an airtight container. Let the cake come to room temperature before serving.
You can also freeze this Keto cake. Simply defrost it in the fridge for 48 hours or on the counter for 24 hours.
More decadent keto desserts with chocolate
- Fudgy Chocolate Avocado Cake (Sugar Free)
- Sugar Free Low Carb Chocolate Birthday Cake
- Keto Chocolate Donuts
- Really Simple Low Carb Chocolate Tart
- Sugar Free Chocolate Cupcakes
Tried this sugar free cake recipe? Give it a star rating below!
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Best Ever Keto Chocolate Cake (Sugar Free)from Sugar Free Londoner
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- 300 g / 10.5 oz unsweetened chocolate ***see notes
- 300 g / 10.5 oz butter unsalted (1 ⅓ cup melted)
- 6 eggs
- ½ cup / 50g almond flour or ground almonds
- 1 cup / 150g powdered erythritol
- pinch of salt
- Heat the oven to 170 Celsius / 340 Fahrenheit. (If you are baking at high altitude, increase the oven temperature by 10 Celsius / 25 Fahrenheit.)
- Melt the butter and chocolate in the microwave (ca 90 seconds - see notes), then stir and wait until dissolved. Alternatively, gently heat in a water bath (a heat proof bowl placed over a pan of boiling water). Set aside.
- In a large bowl, beat the eggs until foamy, then add the sweetener and mix well.
- Add the melted chocolate and butter along with the almond flour and stir with a spoon or spatula until just combined.
- Line the bottom of a 20 cm / 8 inch springform with parchment paper and grease the sides with butter. Pour in the cake batter and bake for approximately 30 minutes on the middle shelf until the top of the cake is firm to the touch, especially in the middle.
- Leave to cool before releasing from the cake tin. Once the the cake is completely cooled, dust with cocoa powder.
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First published in November 2018. Updated and republished in June 2022.
One of my favouries from Katrin!
Made this cake today! Beautiful! I'm new to a keto lifestyle. Is this cake a total of 398 calories?
I baked my cake in a 20 cm cake tin..... after 30 mins it was still very "wobbly" in the centre so baked for a further 10 minutes. Still very soft in the centre. Slightly firm on the top. Tasted at room temperature and was very gooey inside. Still tasted great! It's now firmed up in the fridge. Is this what it should be like? Do I need to lower the temp and cook for a little longer as I do with other cakes?
It is a very fudgy cake. I would not over-bake it.
Hi Katrin from Texas...where I love all your recipes! This one looks great, too. My question is about the 1 c powdered erythritol. If I only have granular sweetener, do I blitz it and then measure it? Or do I measure a cup and then blitz that cup and use all of it? (or to taste of course)
This has always been confusing to me.
Thank you so much for all your work on these recipes. You truly have a gift!
Hi Margret, measure after you powder it. (Granulated sweetener is denser and therefore heavier than powdered sweetener.) And keep in mind that this amount of sweetener is for use with unsweetened chocolate. If you're using a sugar free chocolate it will be sweet already which means you'll need less additional sweetener.
Could you use Lily's 90% chocolate?
Yes, of course! You may want to reduce the amount of additional sweetener then as it's sweeter than the dark chocolate I used.
Hello your recipes are brilliant, do you have a full recipe book for baking only, would love to purchase one
Both my Keto Cookies Cookbook and my Keto Bread Cookbook are all baked recipes. The Keto Desserts Cookbook contains mostly baked recipes.
Thank you for the chocolate cake recipe. I was wondering if i could sub cocoa and butter for the chocolate? I have a hard time finding unsweetened chocolate in the grocery. I did find some once but it was not a good quality. The taste was very bitter and grainy.
Thank you for your answer.
Hi Ruth, that would not work because the cacao butter in chocolate is much firmer than butter. See if you can find 90% dark chocolate instead. It's very low in sugar and quite easy to find. I often buy the 90% Lindt. It's delicious.
Hi should I be adding baking powder to make the cake rise?
Hi Karen, I'm not sure whether that would make a big difference. There is very little flour in the cake. But it certainly would not harm it.
I made this with extra fine almond flour and it came out like concrete. Is it better to use ground almonds or alternatively, how much almond flour should I use?
I keep coming back to your recipes - your olive oil cake is just superb - in some of them you detail the flour element so I know which one to use but others you just say almond flour or ground almonds with no difference in amounts.
Thank you for your recipes.
Hi Andreah, I did use ground almonds in this recipe, but since it is not a large amount I did not think it would make much difference whether you are using superfine almond flour or ground almonds. I think the key is to serve this cake at room temperature, which means it’s definitely not rock hard. Do you think this may have been part of the issue?
Don't worry, it will soften at room temperature. Dusting with powdered sweetener and raspberries will be nice, I'd do this just before serving.
Totally delicious and light! I did mine in 2 8inch tins cooked for 25mins. Sandwiched with cream and raspberries.
Hi, with regards to the Montezumas chocolate, did you use the Absolute black 100% one?
Yes, that is the one I use.
Lovely rich decadent cake, easy to make and so satisfying ! Made it in a larger tin but needed another 8-10 minutes to cook 🙂
Can I substitute the butter? Cant with this.
I don't recommend it. There's a lot of butter in this recipe and if you substituted with coconut oil, it just would not taste the same.
I made this and I’m not sure if I did something wrong?
I found that once cooked and cooled all the fats settled and went hard on the base of the cake. Should that happen? Tastes divine though!
No, this did not happen to me. May I ask which chocolate you used? It's possible that it has something to do with additional ingredients in the chocolate. Or it's a temperature issue. Chocolate can split when it is heated too much, and you can also have issues when melted, hot (not warm) chocolate it is mixed with fridge cold eggs. Be sure all your ingredients are room temperature or close to room temperature.
This cake is delicious, i added chopped hazelnuts ,definately 5 star
Your recipes never disappoint and are a hit in my household with all family members (including non-keto baking purists). Thank you
Would it work to just use a gluten-free flour mix, since I’m out of almond flour?
I think it would, yes.
I've tried your recipe for the 1st time today, the aroma from the over right now is heavenly!
I followed the recipe quantities exactly, even weighing each ingredient before adding into the batter, and saw that my batter was a lot more runny than the batter in your video, so I added another 50g of almond flour (so 100g in total instead of 50g as in your recipe).
I used Coti's Zero Sugar Milk Chocolate (I love to support local businesses in South Africa) http://www.cotizero.co.za/product/coti-zero-added-sugar-milk-chocolate-bars/
The cake came out.. well to be frank... freaking AMAZING!!
I also had to bake it for an extra 25min longer, as the cake was wobbly, like jelly, and still runny in the middle when i tested it at 30min & at 40min
In total I had to bake it for 55min at 170 degrees celcius, but now that its done... Holy Moly its incredible!!!
Thanks so much for sharing this recipe 😉
Janet M Watson
I am going to make this cake tomorrow. I am not sure which chocolate to use. I can get Ghirardelli - why type though ? I know it has to be specific. Thank you. I can't wait to make this !!
I haven't tried the Ghiradelli, but I know bloggers in the US use it. There is an unsweetened one. I normally use the Lindt 90% or the Montezuma's unsweetened chocolate. Both are wonderfully creamy and mild. Keep in mind that when you use unsweetened over 90% chocolate you have to use a little more sweetener. Be sure to taste your batter before baking!
Best chocolate cake!!
Thanks for all the great recipes.
You've turned me into a Allulose convert. Would you recommend it in this recipe? If so, can you tell me how much Allulose to use, rather than the erithrytol?
Of course! I would start with the same amount. Then, see if you need to add a little more (it's slightly less sweet than the usual 1:1 sugar replacements).
Look great n delicious
Did not make it yet, planning to do this later this week. I am curious if I this pie can also be put in the freezer, since the full recipe is too much for one person alone.
Thanks for answering
Yes, I've frozen this cake without problems.
Thanks @Katrin Nürnberger
Oh, forgot to say: I wanted to cut the cake so I could layer it with creme, but since this was the first time I made this cake I didn’t want to jinx it so I did not layer it. Now that I’ve tried the recipe I would say that The cake could work in layers, but I’d be careful as it is a very heavy cake. You could end up with a disaster. If you decide to layer, bake the cake longer than the recipe recommends. The cake is so fatty that extra time in the oven will absolutely not Dry the cake up.
Made the cake yesterday and it is a really Good recipe. The cake is super chocholaty, heavy and truly Devine. Will make it again for sure.
hi Cecilie, glad you made the recipe work for you!
When you say you added more sugar substitute - how much more would you say you added? I've not tried using sugar substitute yet and this will be my first bake on keto.
Hi Lizzie, in case Cecilie does not see this - start by adding as much as stated in the recipe. Then taste the cake batter and decide if you think it needs more. 🙂 Do check though that you're using a 1:1 sugar substitute. Some sweeteners are twice as sweet as sugar. And once you've added too much, there's no way back!
Do you think I could substitute the butter for anything? Our son is dairy free and it’s so hard to find a cake that suits us all!!
HI Karen, I normally just substitute butter with coconut oil. I haven't tried it in this cake. I guess a neutral coconut oil would be essential here as it's a lot of butter in the recipe. Maybe try halving the recipe and make a test run? Also consider trying out this chocolate avocado cake, it's dairy free.
Hi! I made this Sunday for my Monday (labor day - 9/7/20) birthday. I shared it with my parents and grandmother and another housemate. They all loved it. Dad said it could use MORE SWEETENER. Most of these "Keto" recipes really skimp on that.
Also, my inspiration for making this was my love of Black Forest cakes for my birthday cake. I made only one layer, and bought sugarfree CHERRY PIE FILLING, and SUGARFREE WHIP CREAM, AND VOILA!
Jennifer in AZ, one year older!
Happy birthday Jennifer! So glad you like the cake, and turning it into a black forest cake is just genius. Yum! The sweetener thing is very personal as your taste buds read just once you cut out the sugar. I feel that many recipes out there are actually too sweet for me. My best tip would be to always taste the batter and add some more if you feel it needs it.
My birthday is coming up and would love to try this recipe for my birthday cake! But I was just wondering, does the cake have that kind of texture that I could cut it in half so I would have two cake layers and filling between them? I was thinking about adding the baking powder to the mix.
Hi Mikaela, I don't think this is the best cake for layering. You want to make a fluffy cake for this, this one is fudge and dense.I have a recipe for chocolate muffins/cupcakes which you could make as a cake, if you bake a little longer.
Loved the cake. Very nice a so simple! **** Thank you
I have another version of this cake which only uses 3 ingredients but this is by far the best keto chocolate cake I have tasted. I have been low carb/keto for 10 years & have tried numerous recipes & I would have to say this is THE Best! Thanks for the recipe
Forgot to add in my previous comment that I added 1 tsp vanilla and about 1/8 tsp espresso powder (as I’m on a chocolate, salt, espresso powder obsession right now). Worth trying.
Wow! This is a fabulous recipe, thanks. I halved the recipe, used a 6” spring form and dusted it with cacao, put strawberry fans on it then gave it a light sprinkle of powdered swerve. It looked beautiful and tasted amazing (maybe too amazing as I could t stop sneaking little slices of the left over). Thank you!
I wish I could have seen it!!! Next time post a picture on my FB page or tag me on instagram 🙂
I have halved quantities too, what is the cooking time for half measures please?
I would go for 25 minutes and then test.