Fluffy soft, creamy white chocolate mousse filled with a rich layer of chocolate cake and topped with a delicious chocolate mirror glaze. This white chocolate mousse cake is the perfect dessert and will impress anyone who has a bite. The recipe is very easy to make, just follow the steps and don’t rush on the freezing times. You will like this chocolate mousse cake so much, you will make it again in no time.
Is it difficult to make?
The short answer is no, the techniques in this recipe are fairly simple and if you follow the instructions you should have no issue making this White Chocolate mousse cake. The one thing worth mentioning is that it does have a lot of steps and waiting times. You should definitely stick to the waiting times especially when it comes to freezing the mousse before de-moulding.
This recipe breaks into three parts a) The Chocolate Mousse b) The Cake layer and c) the Mirror Glaze. You can find the full ingredient list at the bottom of the post but here is an overview of what and why we use it to achieve the perfect chocolate mousse.
White Chocolate Mousse
The chocolate mousse is made using a culinary technique using heavy cream and gelatin. By whisking the heavy cream to soft peaks it remains fluid enough to fill a mould. The gelatin will set the heavy cream so it doesn’t run all over your plate when its served. We can add flavors to the mousse by folding it into the cream. The only role of the milk in this step is to dissolve the gelatin, since you cannot heat the heavy cream to dissolve the gelatin, we dissolve it in hot milk which wont impact the texture or flavor of the mousse.
Sheet Cake Layer
The cake layer is made using a simple yet delicious cake recipe, by adding three equal (almost) amounts of flour, sugar and butter we achieve a soft yet rich texture and flavor. We use eggs as binding and leveling agent with some additional help from 1/2 a teaspoon of baking powder. Don’t forget, we always add vanilla extract to eliminate any egg smell.
To make a shiny and even mirror glaze, we need to make it runny and shiny. For this reason we make a water based glaze and add sugar and cocoa for flavor, color and sweetness. The corn syrup will add to the shine and consistency while we add whipped cream for texture and flavor. The gelatin will make it set in place so that it doesn’t run all over the place.
For this cake recipe I treated myself to a new silicon mould, I have to admit I am a total kitchen gear addict, but look at the design isn’t it just beautiful? My kitchen stocks quite a few cake moulds but this is my first Silikomart. The design I went with is called Lana which is a smooth winding log shape. I was very close to leaving the mirror glaze out completely simply because the shape was so beautiful. Now with this being said, you can use ANY silicon mould for this as long as the capacity is around 1 liter or just under 40 fluid ounces. Other than this, you will also need basic kitchen equipment which I am listing here:
- A Silicon cake mould with a capacity of around 1000ml or 38 Fluid Ounces
- A Hand or Stand Mixer to whisk the egg white
- Heatproof Mixing bowls to melt the chocolate and mix the batter in
- A rubber or silicon spatula
- A medium sized sauce pan
If you want to see all the equipment I use, please check the links in the recipe. Note that these are affiliate links!
Temperature & Time
Times and Temperature is very important with this recipe. Do not de-mould the mousse unless its completley set and frozen otherwise it will fall apart.
- The first layer of mousse needs around 20 minutes in the freezer, this is enough to support the cake layer and top with the remaining mousse.
- Before de-moulding you must let the whole mould freeze for at least 6 hours, anything sooner than that will deform the cake while demoulding.
- Baking temperature for the cake layer is 170c or 340f
Tips & Tricks
The best tip I can give you when making this recipe is, follow the instructions carefully. Read the recipe a couple of times before you start to ensure you are prepared for all the steps. This is not a difficult recipe at all, but you have to be prepared and follow the instructions as closely as possible.
The Mirror Glaze is definitely NOT a must here, instead you could make a smaller amount and sprinkle it over the mouse (while it is still frozen)
Another important tip, let the chocolate cake cool completely before adding it to the mousse layer. Warm cake will liquify the gelatine and you wont get a creamy texture when the cake is done.
White Chocolate mousse cake
White Chocolate Mousse
- 200 gram Heavy Cream
- 200 gram White Chocolate
- 4.5 gram Gelatin
- 120 gram Full Fat Milk
- 110 gram All-purpose flour
- 110 gram Crystal Sugar
- 110 gram Unsalted Butter well softened
- 3 Tbsp Cocoa Powder
- 4 Large Egg
- ½ Tsp Baking Powder
- 1 Tsp Vanilla Extract
Chocolate Mirror Glaze
- 7 gram Gelatin
- 80 gram Water
- 20 gram Corn Syrup
- 80 gram Sugar
- 40 gram Cocoa Powder
- Preheat the oven at 160C (fan assisted) or 320 Fahrenheit. Prepare your mould, I used a silicon loaf pan but you can really use any form that's around 10.4 x 5.5 inches long and wide and has a capacity of 1000ml or 33.8 Fluid Ounces.
- In a medium sized bowl, combine the flour, cocoa powder and baking powder. Whisk and set aside until needed.110 gram All-purpose flour, 3 Tbsp Cocoa Powder, ½ Tsp Baking Powder
- In a medium sized heat proof bowl, combine 2 Eggs and 1 Egg Yolk from the remaining Eggs along with half of the sugar and the vanilla extract. lightly whisk together. Add the softened butter.Add hot water (60-70c) to a large sauce pan, please the bowl with the egg, sugar and butter into the sauce pan. Now whisk with an electric mixer until fluffy and pale. This should take around 6-7 minutes.110 gram Crystal Sugar, 110 gram Unsalted Butter, 4 Large Egg, 1 Tsp Vanilla Extract
- Sift half of the dry ingredient mix into the fluffy egg/sugar/butter mix and fold with a spatula until combined. Now add the remaining mix and fold until combined. Set aside until needed.
- Combine the egg white from the remaining eggs in a large bowl and whisk with an electric mixer until lightly fluffy. Now add 1/2 of the remaining sugar and whisk for 30-40 seconds until stiff peaks form. Add the remaining sugar and whisk for another 30-40 seconds. Now fold the meringue into the cocoa batter one third at a time until well combined and smooth. Pour into the mould and bake for 20-30 minutes at 170C or 330F or until a wooden skewer test comes out clean.4 Large Egg, 110 gram Crystal Sugar
White Chocolate Mousse
- In a large bowl, whisk the heavy cream until medium stiff. It has to still be runny so don't whisk all the way. Divide into two equal portions and store in the fridge until needed.Now put half of the gelatin in a cup of ice cold water and let it rest for 10 minutes or until needed. ( you will need to do this again after with the remaining gelatin)200 gram Heavy Cream, 4.5 gram Gelatin
- Note, this step is performed with half of the ingredients, you need to do this twice, once to fill the half of the mould, then add the cake layer and then add the 2nd half of the mousse. Place a small heatproof bowl into a sauce pan with hot water, note that this is NOT a Bain Marie, so the bowl CAN touch the water. Add the chocolate and stir until almost dissolved. When only a few pieces of chocolate are left, remove it from the sauce pan and stir until completely dissolved. Microwave half of the milk to 80c, drain the water out of the gelatin and place it into the hot milk. Stir a bit with a spoon to fully dissolve it. Now add it into the chocolate and stir until smooth and combined. Whisk in half of the heavy cream until smooth and combined.200 gram White Chocolate, 4.5 gram Gelatin, 120 gram Full Fat Milk
- Pour the white chocolate mousse mixture into the silicon mould and place it into the freezer for 20-30 minutes. It doesn't need to freeze solid at this stage but must be strong enough to support the cake layer.
- While the mousse is setting, trim the cake edges and slice it into two equal layers. Try and get them as even as possible. The kids can have the trimmings 🙂
- Now repeat the stem with the white chocolate and heavy cream with the remaining ingredients. Its now time to assemble the mousse. Place the middle cake layer into the form and pour the remaining mousse over it to fill the rest of the form. Shake it a little to remove any bubbles but be careful not to move the cake layer. Now add the final cake layer which will act as the bottom of the cake.Place it in the freezer for no less than 6 hours. Removing it any sooner than that will leave marks on the cake or even break it when de-moulding.
- In a medium sauce pan, combine the water, sugar and cocoa powder. Stir until smooth and fully dissolved (this might take a bit since cocoa powder is hydrophobic) Now add in the Corn Syrup and bring the mixture to a boil. Let it boil for no more than 20-30 seconds and take it off the heat. Pour into a heatproof container through a sieve to remove any bubbles and cocoa clumps. Now let it cool until it reaches 28c or 85F.7 gram Gelatin, 80 gram Water, 20 gram Corn Syrup, 80 gram Sugar, 40 gram Cocoa Powder
- To pour the glaze over the mousse cake evenly, the best way to do this is over a roasting pan and prepping it up with a couple of cups or glasses. Use a palette knife to clean off the edges and let it set.