Heavenly Chocolate Mousse Cake

Preparation: 40 min
Cooking time: 35 min
Waiting time: 2 hrs
Portion: 4-6 portions
Level: 4/5

Ingredient

1. Strawberry jelly
   -Strawberry marmalade: 110 gr
   -Water: 30 ml
   -Sugar: 10 gr
   -Gelatin: 5 gr sheet or powder
2. Chocolate sponge cake
   -All purpose flour: 45 gr
   -Cocoa powder: 25 gr
   -Egg: 3
   -Cooking oil: 25 ml
   -Milk: 15 ml
   -Sugar: 70 gr
   -Cream of tartar: ½ tsp or replace with 3 ml lemon juice
3. Chocolate mousse
   -Egg yolk: 1
   -Sugar: 35 gr
   -All purpose flour: 10 gr or replace with 10 gr corn starch
   -Milk: 150 ml
   -Unsalted butter: 20 gr
   -Cocoa powder: 15 gr
   -Gelatin: 5 gr – sheet or powder
   -Whipping cream: 200 ml (35% fat) – whisked with 15 gr granulated sugar
4. Chocolate ganache
   -Cocoa powder: 20 gr
   -Whipping cream: 60 ml (35% fat)
   -Unsalted butter: 40 gr
   -Sugar:25 gr

Decoration
-Fresh strawberry: 50 gr
-White/ milk/ dark chocolate: optional

Kitchen utensil
-Mousse ring 18cm: 1
-Round cake pan 16 cm: 1

Instruction

1. Strawberry jelly

• Pour 110 gr strawberry marmalade (you can read the recipe here), water and sugar to a saucepan, stir well. Cook at low heat until it starts to boil.
• Add soaked gelatin to the saucepan, stir until it is completely dissolved. Chill at room temperature
• Place plastic wrap inside a 16 cm mousse ring and pour the chilled strawberry marmalade that cooked into. Cool it in fridge for 1-2 hours.

2. Chocolate sponge cake

• Preheat the oven at 175 Celsius degree in 15 min
• Separate the egg yolk and egg white in 2 bowl
• Add a pinch of salt and cream of tartar into bowl of white egg
• Use egg whisk machine to beat the egg white until small bubbles appear
• Slowly add the sugar in mixing bowl, then whisk the egg white at high speed until soft peak (meringue).
• Add separately each egg yolk to meringue bowl and whisk at slow speed.
• Slowly pour and whisk oil and milk into the mixture
• Mix well the cocoa powder with all purpose flour.
• Sieve the flour mixture to mixture bowl. Use the spatula and fold the batter until the flour completely blended
• Place the parchment paper to the cake pan. Pour the batter into pan.
• Bake the batter at 175 Celsius degree in 30-35 min until it baked (the surface bounces when pressing the finger on it).
• Remove the sponge cake out of pan and cool on rack.

3. Chocolate mousse

• Whisk egg yolk and 35 gr sugar in a bowl until the york turns to light yellow color
• Add and whisk 10 gr all purpose flour or corn starch in whisking bowl
• Boil 150 ml milk with 20 gr unsalted butter at low heat. When the butter is completely melted, add 15 gr cocoa powder and stir well until the cocoa powder completely dissolved. Turn off the heat and cool cocoa milk down at 50-55 Celsius degree
• Pour gradually the cocoa milk in whisked york bowl and stir well.
• Pour the york-cocoa milk in a saucepan and cook at low heat. When the milk start to boil and condense, turn off the heat.

The cocoa milk don’t need to be sticky and condense as custard.

• Add 5 gr soaked gelatin to hot cocoa milk and stir until the gelatin completely dissolved. Cool and leave aside.
• Whisk 200 ml whipping cream at soft peak. Divide whipped cream into 2 parts and add each part to cocoa milk. Fold and mix them up until, then we’ll have chocolate mousse.

Note: you need to let cocoa milk mixture chill completely before mixing it with whipped cream.

4. Chocolate ganache

There are 2 ways to make chocolate ganache, one is made with dark chocolate, while the other is made with cocoa powder. Here is the instruction.

Option 1: Ganache made from dark chocolate

1. Add 60 gr dark chocolate chips (or chopped dark chocolate) and 10 gr butter in a clean bowl.
2. Boil 60 ml whipping cream at low heat.
3. Pour the hot whipping cream into chocolate bowl
4. Use a wooden spoon to stir the mixture until chocolate dissolves completely. Then we have chocolate ganache. 
5. Chill at room temperature.

Option 2: Ganache made from cocoa powder

1. Cook 40 gr butter with 70 ml whipping cream in a saucepan until the butter melt. Stir well with wooden spoon.
2. Add sugar and cocoa powder in the saucepan and quickly stir until the sugar and cocoa powder completely dissolved.Then we have chocolate ganache. 
3. Chill at room temperature. Ganache that made with this way is thicker and stickier than option 1 so please note to stir it oftenly.

5. Assemble

• Cut the sponge cake into 2 part (2 cake layers).
• Place the parchment paper into springform. Put the 1st layer of sponge cake and then pour ⅓  chocolate mousse on it. 

Please note that if you use the 18 cm cake pan, you need to use the 16 cm mousse ring or knife to trim the sponge cake (each layer should be around 16cm)

• Unwrap the strawberry jelly and put it on the mousse and pour ⅓ chocolate mousse on jelly layer. 
• Repeat the steps with second layer sponge cake. 
• Smooth the surface by using cake smoother. Place the springform in fridge for 30 minutes to harden the mousse.
• Remove the mousse cake from the springform by using a warm towel and wrap it around the mold for seconds to make the mousse melt, then you can remove the mold easily.
• Slightly pour the chilled ganache on cake surface. Use a knife or cake smoother to spread ganache surface. 
• Chill the whole mousse cake in fridge in 30-60 min before serving
• Decorate the cake with chocolate and fresh strawberries. Reserve in fridge and best used within 2-3 days.