Tuesday, August 11, 2009

Layered Milk Chocolate Mousse Cake

Layered Milk Chocolate Mousse Cake
Home Cooking

This cake could have been PERFECTION if only I followed my instincts.

Unfortunately, I got duped by a recipe typo.


Here's the story:

At the risk of sounding like one of 'those people' who give lame excuses for everything, I'll go full steam ahead with my case. I was looking through my collection of recipe books, trying to find something that would be visually impressive and crowd-pleasing. 'Chocolate' seemed like a safe bet to me because you can do 'exciting' chocolate desserts like fondants and souffles that seem fancy and also taste awesome. One of the top contenders was the chocolate mousse cake I made ages ago (it's still one of my favorite and most successful baking attempts to date) but I did feel like that would be passing up on the opportunity to try NEW recipes.

As luck would have it, I found ANOTHER mousse cake recipe in Nick Malgieri's 'The Modern Baker'. It's a different type of mousse cake - layered chocolate sponge and milk chocolate mousse rather than a baked mousse cake batter. The photograph looked mouth-watering and also very pretty so I knew that this would be the cake of the day.

The mousse cake recipe itself called for a 'chocolate genoise' to be made, with a reference to a different page in the book. That recipe was for a classic genoise and some substitutions were given, should you wish to make a chocolate or vanilla genoise. I looked at the ingredient substitutions for making a chocolate genoise and felt suspicious immediately.

It was basically suggested that you replace 1/2 cup of all-purpose flour and 1/4 cup of cornstarch with 1 cup of all-purpose flour, 1/3 cup of cornstarch and 1/4 cup of cocoa powder. I admit that my mental maths is not as reliable as it was back in the day but you don't need genius-level IQ to realize that 1 cup of flour is much greater than 1/2 cup of flour.

I re-read this instruction several times before feeling confident that I was interpreting it right. I toyed with the idea of Googling the recipe online to confirm the quantities but decided against it. My logic was that maybe the chocolate version was supposed to be more dense and who am I to question the recipe?

Once I actually got to the step of folding the flour, cornstarch and cocoa powder into the egg mix, I knew that it was wrong. Prior to the addition of the dry ingredients, the egg batter was light, fluffy and voluminous. Once the last of the flour was added, it was thick, viscous and sticky. The recipe suggests that you run the batter to all the sides of the cake pan. My batter would barely spread, let alone run. I felt pretty apprehensive at this point but thought: maybe the batter will rise in the oven.

It didn't rise nearly as much as it was supposed to. The result was a heavy, flat, disc-like cake. I considered remaking the whole thing but at that point, didn't know what the CORRECT quantities were and also felt reluctant about wasting 6 eggs in the first cake. I ended up slicing the cake up to try and salvage what I could. It tasted 'edible' and I figured that once it was drenched in syrup and buried under the mousse, it might be reasonably disguised.

Now that I've had the benefit of online research, I can CONFIRM that the quantities WERE wrong. I found the recipe for the chocolate genoise here (just scroll down). What is printed as '1 cup of all-purpose flour' in the book is actually meant to be 1/3 cup. AH HA! I've copied out the CORRECT measurements in the recipe below.

Layered Milk Chocolate Mousse Cake
Makes 1 x 23cm (9in) cake


For the chocolate genoise
  • 3 large eggs
  • 3 large egg yolks
  • pinch of salt
  • 3/4 cup sugar
  • 1/3 cup all-purpose flour
  • 1/3 cup cornstarch
  • 1/4 cup alkalized (Dutch process) cocoa powder
For the syrup
  • 1/3 cup of water
  • 1/4 cup of sugar
  • 2 tsp vanilla extract
For the milk chocolate mousse
  • 3 cups heavy whipping cream
  • 1/3 cup sugar
  • 6 large egg yolks
  • 345g good quality milk chocolate, chopped into small pieces
  • 115g bittersweet chocolate, chopped into small pieces (I just used a combination of Cadbury's dairy milk and Old Gold because that's what I had in the fridge)
For the finishing touch
  • 1 cup heavy whipping cream
  • 2 cups milk chocolate shavings (about 225g)

First, make the chocolate genoise...

1. Preheat your oven to 180 degrees Celsius and set a rack to the middle of the oven. Butter a 23cm (9in) diameter springform cake tin and line the bottom with a piece of baking paper cut into a circle.2. Fill a medium-sized saucepan half way with water and bring to the boil. Reduce the heat to a simmer.
3. Whisk the eggs, egg yolk and salt gently in a bowl and prop it over the saucepan. Whisk continuously and gradually add the sugar in a steady stream until all the sugar is added and the mixture is lukewarm.
4. Pour the egg and sugar mix into a stand-mixer and beat on medium-high until the batter has tripled in volume and the side of the bowl is cool to touch.5. In a separate bowl, combine the flour, cornstarch and cocoa powder. Set a sifter nearby.6. Sift 1/3 of the dry ingredients into the egg batter. Fold it in gently to incorporate all the flour and make sure there are no lumps. Add 1/2 of the remaining dry ingredients and fold. Repeat with the final amount.
7. Pour the genoise batter into the prepared cake tin and gently smooth the top. Pour the batter around to coat the sides of the pan to the top (this helps the cake rise evenly rather than in a dome-shape).
Note: this batter is WRONG - yours shouldn't be this 'stiff'

8. Bake for 25-30min until the cake is well-risen and the middle feels firm when you press down with your fingertips.
9. Remove the tin from the cake on a cooling rack and invert so that it is the right way up. Cool to room temperature. Slice the cake into 3 layers horizontally. You will be using 2 of the layers so wrap up and freeze the third layer for some other time.
My bad sponge :(

Make the sugar syrup...

1. Put the water and sugar in a small non-stick saucepan and bring to the boil.
2. Remove from the heat and stir in the vanilla extract.

Make the milk chocolate mousse...

1. Combine 1 cup of cream and the sugar in a medium saucepan and whisk to blend. Place over low heat and bring to a full rolling boil. Meanwhile, set a fine strainer over a clean bowl and place this near the stove top on which the liquids are heating.
2. Whisk the egg yolks together in a small bowl to break them up. When the cream and sugar boils, whisk 1/3 of it into the yolks. Return the liquid to the boil and whisk away.
3. Whilst you're whisking the cream and sugar, return the yolk mixture into this saucepan. Whisk constantly until the cream thickens slightly (about 15sec after adding the yolks).
4. Remove the pan from the heat but don't stop whisking. Quickly strain the sauce into the prepared bowl. Whisk continuously for about 30sec to cool down so that the eggs don't scramble.5. Combine the chocolate pieces in a large bowl.
6. Pour the hot custard cream over the top and shake the bowl to make sure the chocolate is submerged. Let it sit and melt for 2min before whisking till smooth. Set aside to room temperature.7. Whip the remaining 2 cups of cream until it holds a soft peak. Place in the fridge till needed.
8. After the chocolate cream has cooled, quickly fold the whipped cream into it.
This mousse really yummy AS IS

Assembling the cake...

1. Line your springform pan with baking paper. Place a layer of sponge down into the bottom of the tin. With a pastry brush, brush 1/2 the syrup solution on evenly.
2. Pour 1/2 the chocolate mousse over the top and use a small spatula to spread it evenly.3. Top with another layer of cake without pressing it into the mousse. Sprinkle with the remaining syrup.4. Pour on the remaining mousse, spread evenly and refrigerate the cake overnight, covered, to set the mousse.5. To unmould the cake, unbuckle the sides and peel away the baking paper. To finish it off, whip the cream and spread it smoothly all over the outside of the cake.6. Use a metal spatula to press the chocolate shavings against the side of the cake. Sprinkle the remainder over the top evenly.
7. To serve, cut the cake using a thin-bladed knife. Wipe the knife with a wet cloth every time you cut it to avoid tracking crumbs through it.

I was really hectic whilst baking this cake. The problem with the sponge (as detailed above) was my main issue. Other problems were relatively minor - I couldn't find chocolate shavings so I grated a block of chocolate myself and used that. It doesn't look as nice as the larger curls but we make do with what we have. Also, I had somehow gotten it into my head that the cake had to be cut with a hot knife. Of course, this melted the bits of chocolate mousse that it came into contact with and thus my cross-section shot of the cake doesn't look that nice.

However... sponge aside, the mousse part of the cake was pretty awesome. Sinful (egg yolk + cream + sugar + chocolate) but definitely good. I did the naughty thing and licked the spatula after I finished pouring the mousse into the pan and it was good then. It's even better after it's set. I didn't give the cake overnight to set because it was eaten later that evening but I had a taste the next day and it really does benefit from the extra setting time so make it in advance if you can.

I got a request from a reader to post up a photo of what the cake is SUPPOSED to look like. Here it is:
From 'The Modern Baker' by Nick Malgieri

It's so ego-shattering comparing that image of perfection with my own less-than-aesthetic effort. In terms of my sponge that didn't work, you can see that the proper version has a thicker sponge layer. The other differences are down to: smaller chocolate curls used, a hot knife used to cut the cake (melded my layers together) and poor lighting.


  1. What a great cake you have there! The sponge didn't turn out as great, but overall I like the look of it.

  2. It's good that you show us the mistake you made. Sometimes, it's important to use common sense rather than strictly follow the recipe.

  3. You should definitely post pictures of the correct form of cake

  4. Hi anonymous! I've uploaded the photo of the cake as it's meant to look, from the book. HTH

  5. I still think your cake looks mighty impressive, A+ for effort too - I am super scared of doing layered cakes as I do not have an ounce of finesse.

  6. Helpful hint: I sometime use a potato peeler and shave curls off blocks of chocolate when I dont have any on hand....

  7. hey. Thanks for this recipe. I followed every step as u sed n it turned out awesome! literally the best cake i have ever made n everyone loved it and the credit goes to you..thank you so so so much..anymore recipes such as these that i can use to wow the family??

  8. Hi aafreen! Glad you liked the cake. Everyone in my family thought it was delicious too. It's one that looks impressive but isn't that difficult to make. As for more recipes, I'm constantly on the look out :)

  9. Thanks so much for this post! I was going to make the Triple Chocolate Cake from the same cookbook and was puzzled by the quantities in the cocoa genoise so I decided to google it! Thank god I found your valuable post! Lets hope I will have a success! Thanks again...