With my son’s birthday getting closer, I knew I should start figuring out what cake I would be making for him. I have several really good cake recipes that are delicious, but I love trying new recipes and not always making the same thing.
I knew for sure that it would be a chocolate cake. Anytime I have ever asked him what flavor of cake or ice cream he wanted, chocolate has always been the answer. So I started searching for a few ideas.
I came across a recipe for a chocolate mousse cake over at Tatyana’s Everyday Food. It looked so good, but not all of the ingredients were Keto, so I kept hunting. A few days later I came back to Tatyana’s chocolate mousse cake and happened to show it to my son. His eyes lit up, so I knew this was the cake I’d be making. It needed some modifications, which weren’t difficult, and it was more involved than my normal recipes, but his birthday only comes ’round once a year, right?
I spread the work over two days since part of it needed to cool completely in the refrigerator. And once finished it needed to set in the refrigerator overnight, so I started working on this cake three days before the celebration.
I made the custard for the mousse on the first day. It didn’t take long at all. You start by whisking the egg yolks, Swerve, vanilla and cacao powder. Once well combined, whisk in the heavy whipping cream. Then whisk the guar gum into the almond milk and add it to everything else. Put all of this in a saucepan on the stove and cook it until it thickens. Then blend in the butter and put it in the refrigerator to cool (or overnight).
The next morning I made the cakes. I whisked the eggs in a stand mixer for almost 10 minutes so that they were super fluffy. Then I slowly folded in all of the dry ingredients until well combined. Next I added the vanilla, coffee extract and avocado oil, in that order. I divided the batter between 2 silicone cake pans and baked for 22 minutes. When they were done, I set them aside to cool completely.
A few hours later I came back to finish up. I whisked 2 cups of heavy whipping cream in a stand mixer until it reached stiff peaks. Then I mixed the gelatin into the water, whisked and heated it in the microwave until the gelatin was completely dissolved. I then added the gelatin to the whipped cream and whisked again for another minute. To finish the mousse, I folded the whipped cream mixture into the custard until it was smooth.
Finally I could assemble the cake! It’s super essential to use cake acetate to keep the layers in place while they set in the refrigerator, unless you have a super tall spring-form pan. I didn’t, so I used the acetate.
I placed one of the cake layers on the spring-form pan, wrapped the acetate around it and secured with tape. Then I spread half of the mousse evenly on top of the cake. I topped that with the second cake and finished with the rest of the mousse.
And into the fridge it went. It stayed in the refrigerator until after dinner the next day. Right before serving I made a simple whipped cream and added a few dollops to the top of the cake.
I think this looked really good, but it tasted even better! It’s light and not overly sweet. And the birthday boy was super, super happy!
Light and Fluffy Keto Chocolate Mousse Cake
For Chocolate Cake:
- 6 eggs, room temp
- 1 cup granular Swerve or Lakanto Monkfruit
- 1 1/2 cups almond flour
- 1/3 cup raw cacao powder
- 2 tsp baking pwder
- 1 tsp vanilla
- 1 tsp coffee extract
- 1/2 cup avocado oil
For Chocolate Mousse:
- 3 egg yolks, room temp
- 1/2 cup granular Swerve or Lakanto Monkfruit
- 1 tsp vanilla
- 1 1/2 tbsp raw cacao powder
- 1 cup heavy whipping cream
- 1/2 cup unsweetened almond milk
- 1 tsp guar gum
- 2 cups chilled heavy whipping cream
- 1/4 cup unsalted grassfed butter
- 2 tsp Great Lakes unflavored gelatin
- 2 tbsp water
For Keto Whipped Cream:
- 1/2 cup heavy whipping cream
- 1/4 cup granular Swerve or Lakanto Monkfruit
- 1/2 tsp vanilla
- Preheat the oven to 350°F. Line two 8-inch cake pans with parchment paper. I used silicone pans.
- Place the eggs into a stand mixer bowl and whisk on high for 8-9 minutes, until eggs are lighter and voluminous.
- Add the vanilla, coffee and then add the avocado oil last. Fold the oil into the cake batter briefly, for about 30 seconds.
- Divide the cake batter evenly between the two pans and spread the batter evenly to the edges. Bake the layers in the preheated oven for 22 minutes, until the center is set. Allow the cake layers to cool completely in the pans before removing.
- While the cakes are cooling make the chocolate custard. In a medium-sized bowl, combine the egg yolks, Swerve or Lakanto Monkfruit , cacao powder and vanilla. Whisk for a minute until a smooth paste forms. Start adding the heavy whipping cream and whisk until the mixture is smooth.
- In a separate bowl, whisk the guar gum into the almond milk, then pour the almond milk into the custard mixture.
- Now pour the custard mixture into a medium sauce pan and cook over medium-low heat for 4-5 minutes, stirring constantly. The custard needs to thicken and coat the back of a spoon well.
- Remove the custard from heat and add the butter. Whisk until the butter is completely melted, then transfer to a bowl with a lid and put it in the refrigerator to cool completely, or overnight.
- Once the custard and the cake layers are completely cooled, or the next day, make the mousse. Pour the 2 cups chilled heavy whipping cream into a stand mixer bowl and whisk on high speed for 3-4 minutes until stiff peaks form.
- In a small bowl, combine the water and gelatin and whisk until smooth. Microwave the gelatin mixture for 20 seconds, stir, and microwave for another 20 seconds. The gelatin should be completely dissolved. Immediately add the gelatin to the whipped cream and whisk on high speed for another 30 seconds.
- Fold 1 cup of the whipped cream into the cooled custard gently. Then add all of the custard to the whipped cream. Fold gently but thoroughly, until the mixture is smooth and even.
- Now begin constructing your cake. Put one cake layer into the bottom of an 8-inch spring form pan. Wrap acetate around your cake and secure. This helps keep the mousse and cakes in place while they set.
- Next add half of the chocolate mousse and spread it evenly to the edges, then top with the second cake layer. Top with the remaining chocolate mousse and spread evenly. Refrigerate the mousse cake overnight.
- The next day, make the whipped cream. Add the heavy whipping cream, Swerve or Lakanto Monkfruit and vanilla into a medium bowl. Whisk on high speed for 3-4 minutes until stiff peaks form.
- You can transfer your whipped cream to a piping bag with whatever tip you like, or you can use a ziploc bag by cutting the corner off of the bag and inserting a piping tip before adding the whipped cream.
- When ready to serve, take your cake out of the refrigerator and transfer to a cake plate. Remove the acetate and top with whipped cream.
*This post contains affiliate links.