This is hands-down the most decadent keto chocolate cake you will ever make. Filled with creamy chocolate pudding, this low carb cake recipe takes inspiration from the famous Brooklyn Blackout Cake. Definitely worthy of a special occasion!
Some occasions call for a truly over-the-top dessert. The sort of dessert that catches everyone’s eye and has the room buzzing with anticipation. Something deeply, darkly chocolatey, that looks so rich and moist you can’t believe it could possibly be low carb or keto friendly.
This keto chocolate cake recipe is it, my friends! It is the most amazing chocolate cake I have ever made in my life, keto or not. And I am not even sure what to call it. Keto Chocolate Blackout Cake is the best I could come up with.
I created this stunning sugar-free dessert for my 50th birthday. Because I think we can all agree that being alive on the planet for half a century is worthy of some serious chocolatey goodness.
I was in heaven from the first bite. My birthday felt truly special and this cake was no small part of that!
Why you will love this cake
This cake is modeled after Brooklyn Blackout Cake, a recipe made famous by Ebinger’s bakery in Brooklyn during World War II. As always with keto friendly desserts, I had to take more than a few liberties to make it low carb.
It’s an amalgamation of three of my popular recipes. The cake layers come from my Keto Devil’s Food Cake, the filling is Keto Chocolate Pudding, and it’s frosted with super creamy Keto Chocolate Frosting. So it’s essentially triple the chocolate in one glorious recipe!
I won’t promise you that this is an easy cake to make. You don’t need any advanced skills but it does take time to make all the components and put them together. So leave yourself plenty of time and enjoy the process.
Because the results are absolutely worth the effort.
Ingredient Notes
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- Almond flour: This is an almond flour based cake, but you can make it with coconut flour as well. Use the batter from my Keto Chocolate Cupcakes instead. The layers should take about the same amount of time to bake but keep your eye on them!
- Sour cream: Sour cream gives the cake layers an incredible tenderness!
- Cocoa powder: Use Dutch process cocoa powder for a deeper chocolate flavor. You can replace a little of with black cocoa if you want it even darker. I wouldn’t use more than a tablespoon or so in the cake and/or the frosting.
- Protein powder: Using whey protein powder or egg white protein powder helps the cake rise properly and hold its shape.
- Unsweetened Chocolate: Unsweetened chocolate gives the frosting a richer flavor and a creamy mouthfeel.
- Sweeteners: I use Swerve Sweetener in the cake, the pudding, and the frosting. I also use a little allulose in the pudding to keep it from re-crystallizing. See the Expert Tips section for more sweetener options.
- Keto thickeners: The pudding takes a little bit of glucomannan or xanthan gum so that it thickens properly.
How to make Keto Chocolate Blackout Cake
1. Prepare the pudding
I used a scaled down recipe of my sugar free chocolate pudding, making only two thirds of it. So I have listed the full instructions in the recipe. You will want to make this part first as it needs time to cool and thicken.
You can make it a full day in advance if you want to break up the process.
2. Make the cake layers
This cake uses the full recipe from the Devil’s Food Cake, minus the frosting. I refer you to that recipe for the full instructions for making the layers.
The cake needs to be completely cool before you attempt to slice the layers in half. If you make them in advance, all the better. Sitting in the fridge for a day helps them firm up more and allows for easier slicing. Wrap them up tightly so they don’t dry out.
3. Prepare the frosting
The cake is frosted with a modified version of my Keto Chocolate Frosting. I made a little more of it, and added additional chocolate and cocoa powder for a super rich, fudgy buttercream. Because of these modifications, I have listed the full instructions in the recipe below.
4. Assemble the cake
Now comes the fun part: putting all the pieces of the cake together!
1. The first step is to slice the layers of cake horizontally through the center to create four thinner layers of cake. Use a serrated knife and take your time!
2. Place one layer on a cake platter. Place some of the frosting in a piping bag and pipe a ring around the outside of the layer to create a barrier for the pudding.
3. Spread half of the pudding inside the ring. Top with another layer of cake, another ring of frosting, and the rest of the pudding. Place a third layer of cake on top.
4. Spread the remaining frosting over the top and sides of the cake. Take the fourth layer of cake and crumble it up in a bowl. Use about half of the crumbs and carefully press them into the sides of the cake.
5. Refrigerate about an hour to firm up the whole cake before slicing.
Expert Tips
I highly recommend breaking up the process over the course of one or two days. You can make the pudding a day in advance and the cake layers can be made one or two days in advance as well. In fact, the cake layers are easier to slice when they have been refrigerated for a little bit. Be sure to wrap them up tightly so that they don’t dry out in the fridge.
Always line the cake pans with parchment to ensure that the layers come out of the pans easily. You still want to grease the pan, and then line them and grease the parchment as well.
Sweetener Options
You can use other sweeteners in every component of this keto chocolate cake, but there are a few things to keep in mind.
- Allulose may make the outside of your cakes brown faster and almost seem a little burnt so keep your eye on them. The pudding will also be softer and take longer to firm up when made with just allulose.
- The frosting requires a powdered sweetener to have the right structure and consistency. And other sweeteners like allulose and BochaSweet may make it softer so add the cream slowly and stop when it’s a spreadable consistency but it’s not goopy.
Frequently Asked Questions
Many people are surprised and delighted to find that they can enjoy cake on a low carb or keto diet. These days there are many delicious cake recipes that utilize alternative flours and sweeteners. I recommend starting with simple recipes like Almond Flour Cake or an easy Keto Mug Cake to get used to these new ingredients.
This luscious keto chocolate cake recipe serves 16 people and has 8.3g of carbs and 4.1g of fiber per serving. If you count net carbs, each slice has only 4.2g of carbs.
Ebinger’s Bakery created the Blackout Cake during World War II. Mandatory blackouts were required to protect the nearby Brooklyn Navy Yard. The cake contains multiple layers of dark chocolate cake with a chocolate pudding filling and plenty of rich, dark chocolate frosting. So the name is very fitting!
More cakes you will enjoy
Keto Chocolate Blackout Cake Recipe
Equipment
Ingredients
Pudding
- 1/2 cup (118.29 ml) heavy whipping cream
- 1/2 cup (118.29 ml) almond milk, Or another low carb milk
- 3 tbsp (3.04 tbsp) Swerve Granular, (or other granular sweetener)
- 2 tbsp allulose
- 2 large egg yolks
- 1/4 tsp (0.25 tsp) glucomannan, or xanthan gum
- 1/4 cup (21.5 g) cocoa powder
- 2 tbsp (2.03 tbsp) butter, cut into two pieces
- 1/2 tsp (0.5 tsp) vanilla extract
Cake
- 1 recipe Keto Devil's Food Cake, (just the cake, without frosting)
Frosting
- 3 ounces (85.05 g) unsweetened chocolate, chopped
- 1/2 cup (113 g) butter, softened
- 4 ounces (113.4 g) cream cheese, softened
- 2/3 cup (157.73 ml) Swerve Confectioners, (or other powdered sweetener)
- 3 tbsp cocoa powder
- 1 tsp vanilla extract
- 2/3 cup (157.73 ml) heavy whipping cream
Instructions
Pudding
- In a medium saucepan over medium heat, combine the cream, milk, and sweetener. Bring to a simmer, stirring occasionally.
- In a medium bowl, whisk the egg yolks until smooth. Slowly add ½ cup of the hot cream mixture into the egg yolks, whisking continuously.
- Slowly whisk the tempered egg yolks back into the saucepan of hot cream. Reduce heat to medium low and sprinkle with xanthan gum, whisking continuously.
- Stir in the cocoa powder and cook until mixture thickens, 3 to 4 minutes, whisking continuously. Remove from heat and stir in the butter and vanilla extract until smooth.
- Pour into a bowl, cover with plastic wrap, and refrigerate 2 to 3 hours.
Cake
- Prepare the cake layers according to the instructions in the Devil's Food Cake recipe.
- Let cool completely, then carefully slice each layer through the middle into two thin layers. (Tip: If you make the cake layers ahead of time, a few hours in the fridge help them firm up enough to slice more easily. Wrap them in plastic so they don't dry out).
Frosting
- Place the chopped chocolate in a microwave safe bowl and melt in 30 second increments, stirring in between until smooth. Alternatively, you can melt the chocolate and butter together in a heat-proof bowl set over a pan of barely simmering water. Set aside to cool to lukewarm.
- In a large bowl, beat the butter and the cream cheese together until smooth. Beat in the powdered sweetener and the cocoa powder until well combined.
- Add the chocolate and vanilla extract and beat until smooth. The mixture will be very thick at this point. Add the cream a few tablespoons at a time until a spreadable consistency is achieved.
To assemble
- Place one layer of cake on a cake platter and pipe a ring of chocolate frosting around the outside edge. This creates a barrier to keep the pudding from oozing out. Spread half of the pudding inside the ring of frosting.
- Add another layer of cake on top and repeat with a ring of frosting and the pudding. Top with a 3rd layer of cake.
- Spread the top and sides of the cake with the remaining frosting. If you want to make a swirl on top of the cake, place the cake on a turntable. Hold a spoon to the center of the frosted top and turn the cake. Move the spoon outward from the center as you turn.
- Take the final layer of cake and crumble it up. Carefully press some of the crumbs into the sides of the cake (you will probably only use about half of the crumbs).
- Refrigerate one hour to firm up before slicing.
Nutrition
Nutritional Disclaimer
Please note that I am not a medical or nutritional professional. I am simply recounting and sharing my own experiences on this blog. Nothing I express here should be taken as medical advice and you should consult with your doctor before starting any diet or exercise program. I provide nutritional information for my recipes simply as a courtesy to my readers. It is calculated using MacGourmet software and I remove erythritol from the final carb count and net carb count, as it does not affect my own blood glucose levels. I do my best to be as accurate as possible but you should independently calculate nutritional information on your own before relying on them. I expressly disclaim any and all liability of any kind with respect to any act or omission wholly or in part in reliance on anything contained in this website.
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Your recipes are fabulous. Easy directions. Thank you.❤️
I can’t use Allulose . It upsets my husband’s stomach. What should I use instead?
Try xylitol.
Haven’t made this yet. Your recipes are always 5 star. Question: can I use my immersion blender instead of continuous whisking when making the pudding?
I have never tried that. I suspect not… I think it will be too fast and cause the pudding to be frothy.
I made this for my birthday…..it turned out perfectly. It was so delicious, no one would guess it was Keto friendly. There was no hint of fake sugar or funny aftertaste. My husband (my guinea pig taste tester) was truly impressed. Thank you for your hard work that makes our journey with Keto so much easier!
Happy birthday!
Any idea how soy protein powder would work in place of the whey protein?
Should be okay in this recipe, especially since the cake is dark so any discoloration won’t be noticeable.
Wow! It was even better than I thought. I made it for my mom’s birthday and she loved it. The instructions are clear and easy to follow and the result is simply divine. Thank you yet another amazing recipe!
Great to hear!
My husband is a chocolate lover and asked for a chocolate cake for his birthday next month. This is it!
I’m looking forward to making it.
Many thanks, Carolyn.
I just finished this, and it’s totally delicious!
Again, thank you.
Only reason I didn’t give you a 5 which frankly most of your recipes usually are is – my cake didn’t rise like yours hence cutting the layers was so hard to do. I’m sure the taste will be great. But I’m a pretty good baker probably because I follow such recipes exactly because you’ve already done the hard lifting with the chemistry part of the recipe – keto recipes really require exacting science if you will. I guess I can get more baking powder but I used it recently without issue but perhaps this is the reason.
And I’ve got to say I thought I’d be in love with the putting the cake together part but between the layers falling apart and the icing coming out of the top of the decorating bag (first time I decided to use it!) I just wanted to put the cake in refrigerator and I’m sure I’ll be excited by tomorrow to try it!
But – that pudding recipe is a 5++++ star recipe and I’ll be making that again and soon!
i don’t often say it, but this cake is almost too rich.
My daughter who seldom enjoys Keto desserts raved over it, preferring the cake to her brownies.
This cake is a must try.
Delighted to hear that! And yes, it’s very rich.
Amazing cake, thank you for the recipe! It is a bit of work to put everything together but oh boy it’s worth it! Only thing I’d change is the amount of sweetener, it was just a bit too sweet for me (maybe it’s just me but I do find that sweeteners sweeten more than I remember sugar did 🤷🏻♀️).
I also have some great pics of it but I can’t seem to be able to upload any together with my note, sorry.
Made this for my husbands birthday. I was a bit intimidated at the thought of slicing the cake layers in half. He volunteered and did it perfectly! The cake was a huge success! Thank you for such wonderful recipes that I can always trust to turn out great! ⭐️⭐️⭐️⭐️⭐️
Would Monk fruit/eriyhritol sweetener work for this or should I purchase Swerve Granular?
That works! Just make sure it’s cup for cup to sugar for sweetness. Some monk fruit sweeteners are 2x as sweet.