This easy chocolate mousse cake recipe makes a moist dark chocolate cake that’s topped with a yummy chocolate mousse.
I’ve been in a chocolate mousse kinda mood lately.
At first, I thought I’d make a French Silk Pie. I wanted something rich and chocolaty, and French Silk Pie came to mind (you can try my French Silk Brownie Recipe if that sounds good to you, too!).
Since my birthday was coming up, I finally ended up settling on this Chocolate Mousse Cake. And it was an awesome decision.
This cake is moist and intensely chocolaty. It’s topped with a super rich and creamy chocolate mousse for the ultimate chocolate dessert!
And all of that chocolate in one little piece of cake meant a very happy birthday for me.
More chocolate cake recipes!
Chocolate Mousse Cake Video
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Chocolate Mousse Cake
Ingredients
Chocolate Cake
- 1 3/4 c. all-purpose flour
- 1 3/4 c. granulated sugar
- 3/4 c. unsweetened cocoa powder
- 2 tsp. baking soda
- 1 tsp. baking powder
- 1 tsp. kosher salt
- 1 c. buttermilk (low-fat ok)
- 1/2 c. vegetable oil
- 2 large eggs
- 2 tsp. vanilla extract
- 1 c. hot water (not boiling)
Chocolate Mousse
- 1 1/2 c. mini marshmallows
- 8 oz. semisweet baking chocolate (chopped)
- 1/2 c. milk
- 2 c. heavy whipping cream
- 1/2 tsp. vanilla extract
Instructions
Chocolate Cake
- Preheat oven to 350 F. Grease a 9x13-inch baking pan. Set aside.
- In a medium bowl, whisk together flour, sugar, cocoa powder, baking soda, baking powder, and salt. Set aside.
- In a large bowl, whisk together buttermilk and vegetable oil.
- Whisk in eggs one at a time.
- Stir in dry intredients until just combined.
- Add hot water and vanilla.
- Whisk until just combined.
- Pour batter into prepared baking dish.
- Bake 30-40 minutes, or until wooden toothpick inserted in the center comes out clean.
- Cool to room temperature.
Chocolate Mousse
- To make the chocolate mousse, add mini marshmallows, chocolate, and milk to a large, heavy saucepan.
- Cook over low heat, stirring constantly, until melted and well-combined.
- Remove from heat, and cool completely.
- In a large bowl, beat whipping cream and vanilla together to soft peak stage.
- Fold whipped cream into cooled chocolate mixture.
- Spread over cooled cake.
- Chill for at least 30 minutes, or until ready to serve.
- Refrigerate any leftovers.
Video
Notes
Nutrition Information
Cake adapted from Food Network.
Karen Cornell says
This was one of the best chocolate cakes I’ve eaten in a long time. It was so moist and flavorful. Easy to make
The mousse as well was easy to make and so delicious. This is definitely a keeper recipe.
Kate says
Thank you so much! I’m glad you liked it!
Linsey says
Hi Kate!
I was thinking of making this is 2 round 9 inch pans. Do you know if the chocolate mousse would hold well as a layer between the cakes?
Thanks!
Kate says
Hi! The chocolate mousse is pretty soft when you first make it. You may have better luck frosting the first layer and then chilling until firm and then placing the second layer on top and then finishing the cake that way. Hope that helps!
Swathi says
Hey, thanks a ton for the recipe.. Is it possible to substitute the marshmallow with something else? I’m finding it really hard to find a pack of marshmallows at the moment😫😥 and it’s my boyfriend’s bday cake, I want it to be perfect.. Any recommendations please? Thanks much!🤩
Kate says
I wish I had an easy substitute for you! Unfortunately, if you can’t find marshmallows, you’d need to find another mousse recipe because the marshmallows provide a lot of the stability for the mousse.
Donna says
Can you use hot coffee instead of water?
Kate says
Hi! I haven’t tried using coffee in place of the water, but I’ve heard from people who have made that swap, and they’ve said that it worked out well for them.
Suzie says
Hello!
This cake sounds divine!
Just wondering if I could make cupcakes with it and if so, what the baking time would be?
Kate says
Hi! I haven’t tried making cupcakes with this recipe, but I don’t see why it couldn’t work. The baking time for cupcakes is usually about 18-25 minutes.
Brooke says
Going to make this cake for my sons 3rd birthday! Would you happen to know the baking time for two 9” round pans ?
Kate says
For a 9″ round cake, it’s usually about 20-30 minutes.
Taryn says
My D loves the tuxedo cake from Costco. I hate baking! But she turned 11 in March 25th (during the dreaded QUARANTINE!) Hubby is germaphobe & hypochondriac so he was freaking out Bc I wanted to order or p/u the tuxedo cake. So I didn’t🙄😔
So, during this time…ordered groceries ( several times now) however, I guess EVERYONE LOVES baking except me…Bc I guess all the regular flours are out?!?! Shopper brought me…Arrowhead Mills all purpose flour ( but Gluten Free!!!)
I think this recipe is easy & I really truly think it would have turned out FAB…but that D GF flour!!!!! Made it extremely gritty!!! I was so sad! My D ate it anyway & we all did….Bc the mousse was delish! And the cake…..I truly think it would have been wonderfully chocolate delicious if it weren’t for that flour.
I hope to try it again 1 day…especially the mousse!
Thank you for the recipe especially since I’m an amateur.
Kate says
I hope your daughter had a very happy birthday!! My older daughter has a birthday coming up soon, and it’s hard for the kids who have birthdays during the quarantine. I’m glad that the mousse was good at least! If you ever have any questions as you go, please feel free to ask!
Ashley says
Hi!! Can the mousse be made and put in the fridge until ready to spread on the cake? I used a 9×13 glass dish but the cake baked right up to the top!! There’s no room for the mouse lol so I figured I would just chill the mousse and then slather it on when we are ready to eat it! Then I won’t care if it goes over the pan ha as I need to travel with it tomorrow!
Thanks!!
Ashley
Kate says
Hi! I think that should work! The mousse keeps well in the fridge, so it should be fine to chill it until you’re ready to serve the cake.
Kristie krebs says
Making this for a birthday cake for a chocolate loving ten year old! Can you make it a day early or is it better theday of?
Kate says
Hi! I haven’t found much difference between the cake on the first and second days. The only difference I’ve noticed is that the mousse sets up a bit in the fridge, and so you may find that you want to let it sit out just a bit if it’s firmer than you want it to be.
Taryn says
We ate it several days after my D b day (& if you read my above comment…my cake was gritty Bc of GF flour HOWEVER…it was still decent) you could make it day before & still eat it several days later…. it’s still very good Bc the mousse is yum. Happy B Day to yours & mine during h th his dreaded time!😔❤️
Janine says
Hi I was thinking about making this for my birthday tomorrow the problem I have Is I only have the big marshmallows . Do you have a thought on how many you think I might need ? I know in this very stressful time you might not have moment but if you do I would appreciate it . God bless stay safe.
Kate says
Hi! Happy (early) birthday!! I do! Five regular (larger) marshmallows should equal 1/2 cup. So, you’ll need 15 of the larger marshmallows. Thank you for your kind words, and I hope you stay safe, too!
Kim says
This is one of my favorite cakes to make. Is it possible to sub the flour and sugar with almond flour and Erythritol?
Kate says
Thank you! I’m not sure! It’s hard to say whether the almond flour would work well or whether other changes would be necessary without having tested it. I wish I had a better answer for you!