Best Ever Keto Chocolate Cake (Sugar Free)

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.

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. Read more about polyols here.

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!

Ingredients

It's hard to believe, but you only need 5 ingredients to make this cake:

• Unsweetened chocolate
• Eggs
• Sweetener
• Almond flour
• Butter

...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.

Recipe tips 

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.

Storage

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!

★ STAY IN TOUCH on FACEBOOK, PINTEREST and INSTAGRAM  for more great food and join my NEWSLETTER for the latest updates and a FREE EBOOK.★ 

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.

First published in November 2018. Updated and republished in June 2022.