Follow CenterCutCook:

The Best Chocolate Cake with Chocolate Mousse Filling

the best chocolate cake chocolate mousse 1

The Best Homemade Chocolate Cake with chocolate mousse filling and chocolate frosting. This is the only chocolate cake recipe you need.

This chocolate cake is for the chocolate lovers out there. It is made from scratch with a decadent chocolate mousse filling topped with homemade chocolate frosting. It is the ultimate chocolate dessert that is perfect for birthdays and special occasions but it’s so delicious that you’ll likely try to find any excuse to make it.

Because of the unusual times we are currently living in, with a global pandemic and all, I’m also going to deem this the must-make dessert of your stuck-at-home 2020 quarantine. If you make one dessert during this time, make this chocolate cake! You won’t be sorry.

the best chocolate cake chocolate mousse 5

There are so many different and delicious chocolate cake recipes out there (eh hem, this recipe for Portillo’s Chocolate Cake), but what makes this a stand out recipe is the chocolate mousse filling, and the most delicious chocolate frosting. You will soon discover, like I have, that there are few things in life better than chocolate cake, with chocolate mousse filling, topped with chocolate frosting.

Homemade Chocolate Cake

There is a time and place for boxed cake mix (I’m a fan!) but there’s also a time and place for a homemade, from scratch chocolate cake. Making a chocolate cake from scratch is not difficult, it just takes a bit more time to measure out all of the ingredients. You’ll need all of the typical cake ingredients including all-purpose flour, sugar, baking powder, baking soda, salt, eggs, vanilla extract, and vegetable oil. And you’ll also need a couple of ingredients that you don’t always find in a cake including boiling water and buttermilk.

Buttermilk tip: If you do not have buttermilk on hand, you can verily easily make a substitution. Add 1 tablespoon white vinegar to a 1-cup measuring cup, then fill the rest with milk. Stir to combine, then allow it to sit for 5 minutes. This milk/vinegar combination can then be used as a buttermilk substitute in this recipe.

the best chocolate cake chocolate mousse 3

Chocolate Mousse Cake Filling Recipe

Chocolate Mousse Cake Filling is actually quite easy to make despite sounding a bit intimidating.

The ingredients you will need to make chocolate mousse for a cake filling include: hot water, unsweetened cocoa powder, milk chocolate chips, heavy whipping cream and granulated sugar.

Making the mousse is simple – all you’ll need to do is whisk together the cocoa powder and hot water. Then, you’ll melt the chocolate chips in the microwave until smooth and add the cocoa powder/hot water mixture to it. With your mixer, you’ll beat the heavy whipping cream and sugar together until stiff peaks form at which point you’ll add in the chocolate mixture and mix until smooth.

You’ll refrigerate the mousse until the cake has cooled completely. This is important. The cake must be cooled completely before you can assemble it.

the best chocolate cake chocolate mousse 2

Chocolate Frosting Recipe

Homemade Chocolate Frosting is what perfects this chocolate cake. All you’ll need is milk, unsweetened cocoa powder, unsalted butter (softened), and 3 and 3/4 cups powdered sugar. That’s it!

This chocolate frosting is made on the stovetop. In a saucepan you’ll combine the milk, cocoa powder and butter and bring it to a boil. Once it comes to a boil, you’ll remove it from the heat and stir in the powdered sugar and use a mixer to combine it. Allow it to cool for just a couple of minutes but not for too long because you want the frosting to be warm while you pour it over the chocolate cake.

Chocolate Cake Decorating Ideas

When it comes to decorating your chocolate cake, you can keep it simple and just sprinkle some chocolate sprinkles on top, or, you can also reserve some of the chocolate mousse filling to pip rosettes on the top of the cake. This is entirely optional.

There you have it. The best chocolate cake with chocolate mousse filling with chocolate frosting. The chocolate lover in your life will be in chocolate heaven!

the best chocolate cake chocolate mousse 4

If you decided to try this recipe, and I hope you will, please take a picture and tag me on social media. I love seeing what you make! I can be found on Pinterest, Instagram, and Facebook. Please use the hashtag @CenterCutCook

Lastly, if you’ve been around here for a while, you know that I usually adhere to sharing only information about the recipe. However, I’m adding a new segment to the bottom of each recipe going forward to include a quote, tip, or personal life experience that I want to share with you and I’m calling it Nourish. Nourish means to provide the body with food or substance necessary for growth, health, and good condition. And while it’s important to nourish the body with food, it’s also important to nourish the mind and soul and that’s what I hope this will accomplish.


Today is Friday, April 17th, 2020. We’re currently in the midst of a global pandemic. Covid-19 has changed life as we know it and we find ourselves sheltering at home and social distancing to help flatten the curve and reduce the spread of this novel virus.

Those of you that have been here for a while know that I lost my husband to cancer, and that in the midst of his cancer treatment, our son was born with a rare disease and he needed two and a half years of dialysis while waiting for a liver and kidney transplant which he’s since received.

Something that I learned during that time when my life was turned upside down that also applies today, and it applies any time you are going through something difficult is that the hard days don’t last forever. Let me repeat it: hard days don’t last forever.

Just as the seasons change throughout the year, there are seasons of life. There are good seasons and hard seasons and seasons that you wish you could fast forward through. If you find yourself wishing you could fast forward through this pandemic to the other side, THAT’S NORMAL!

What I have also learned is that some of the hardest days of your life might lead you to some of the best days of your life. Hang in there. It’ll get better.

Have a great week!


Looking for more delicious chocolate dessert recipes? Try:

The Best Chocolate Cake with Chocolate Mousse Filling

the best chocolate cake chocolate mousse 6

Prep Time: 20mn
Cook Time: 30mn
Total Time: 1hr 10mn


Need to convert the measurements? Click here!


  • 1/2 Cup hot water
  • 4 Tablespoons unsweetened cocoa powder
  • 1 1/2 Cups milk chocolate chips
  • 2 Cups heavy whipping cream
  • 2 Tablespoons granulated sugar
Need to convert the measurements? Click here!


  • 6 Tablespoons milk
  • 3 Tablespoons unsweetened cocoa powder
  • 1/2 Cup unsalted butter (softened)
  • 3 3/4 Cups powdered sugar
Need to convert the measurements? Click here!


  1. Preheat the oven to 350 degrees.
  2. Grease and flour two 8” cake pans or line with parchment paper.
  3. Boil 1 cup water.
  4. In a large bowl, stir together sugar, flour, cocoa powder, baking powder, baking soda and salt.
  5. To that add: eggs, milk, oil, and vanilla extract. Use your mixer to beat on medium speed for about 2 minutes.
  6. Slowly stir in the boiling water.
  7. Pour the batter evenly in the cake pans.
  8. Bake 30-35 minutes, or until a toothpick inserted comes out clean.
  9. Leave the cakes in the pans for about 5 minutes to cool before transferring them to the cooling rack to finish cooling.


  1. Whisk together cocoa powder and hot water.
  2. In the microwave, melt the chocolate chips just until smooth. Add the cocoa mixture to the chocolate chips and stir well. Allow mixture to cool to room temperature.
  3. In another bowl using your mixer, beat the heavy whipping cream and sugar until stiff peaks form. Mix in the chocolate mixture until well combined and smooth.
  4. Refrigerate until cake has cooled completely.


  1. In medium saucepan, add milk, cocoa powder, and butter. Bring to a boil then remove from heat.
  2. Mix in powdered sugar and use a mixer to smooth the frosting. Cool 10-15 minutes.


  1. Use a sharp knife and cut each cake layer in half, making 4 layers.
  2. Place the first cake layer down on a cake plate, then spread chocolate mousse until even. Add another cake layer and spread more chocolate mousse. Keep repeating, making sure you spread mousse on the top of the cake as well. Then, spread a thin layer of chocolate mousse around the sides of the cake.
  3. Refrigerate 30 minutes.
  4. While cake is cooling, make the frosting.
  5. Take the cake out of the refrigerator and pour the warm frosting over the cake. Use a spatula to spread the frosting while you are pouring it.
  6. Refrigerate until frosting has set.
  7. You can use any leftover chocolate mousse to pipe rosettes on the top of the cake (optional). Then top with chocolate sprinkles if desired.

Leave a Comment

Click to Load Comments