How to Make: Japanese Chocolate Truffle Sponge Cake (チョコレートケーキ)

Yesterday, almost all the shops were closed in the city because of Hurricane Irene.  So what to do when you have the extra time to stay in all day?  Well I baked a Japanese-style chocolate cake!  It is my moist, dense, and fluffl-y at the same time, Chocolate Truffle Sponge Cake.  Beware thought, it is extremely rich. You really only need a tiny slice of it to get satisfaction.  If you have a huge piece, you might actually throw up. Since this is a sponge cake, the amount of butter or oil in the cake is much much less and the texture is lighter which contrasts with the dense chocolate ganache.  I baked mine in a 16 cm (6 inch) cake tin, to make a smaller cake but if you're using a 20cm/8 inch tin, just multiply it by 1/3.  I use 70% chocolate for the frosting. You can always use semi-sweet or bittersweet chocolate chips for this cake.  This is my favourite type of cake, which is also known as Japanese style, because it tastes like chocolate, not sugar, and is not too sweet all. Japanese cakes don't use buttercream frosting recipe because it's way too sweet. Instead they use what I made a ganache which is just chocolate and cream, like a truffle.  I see these types of chocolate cake in Asian Supermarkets all the time, so I thought of giving it a go!  It is the best! The finishing touches are the dusted cocoa powder and the piped whipped cream, it makes it so elegant! It's best to use the metric system when baking (actually for any cooking), but for those people that have not converted, I've listed the imperial measurements on the right side of the page.  There's no reason for you not to try it now!

Chocolate Truffle Sponge Cake (チョコレートケーキ)
Yields- (the 16 cm/6 inch)- 8 servings (the 20 cm/8 inch)-12 servings
Preparation Time-20 min
Cooking Time-45 min
Overall Time- 3 hours

Ingredients:

Cake:
65 gm All-purpose flour (2/3 cups)
15 gm Corn starch or Potato starch (2 tbsp)
100 gm of white sugar (1/2 cup)
2 eggs, separated
50mL of milk (1/4 cup)
30 gm of butter or oil (3 tbsp)
30 gm of unsweetened cocoa (1/4 cup)
10 gm of instant coffee (1 tsp)
5 gm of salt (1/2 tsp)

Filling and Ganache:
110 gm of Dark/Black 70% Chocolate (4 oz)
110 mL of Cream (Coffee or Heavy cream will do) (1/2 cup)
10 gm of instant coffee *optional* (1 tsp)

Decoration:
Some extra cocoa
Whipped Cream

Preparation:
1.) Preheat oven to 170 C/350 F

2.) Line the cake pan with parchment paper

Cake Batter:

1.) Beat the egg whites in a bowl until soft peaks form.  Add the sugar gradually while beating the egg whites until medium-stiff peaks.  The egg whites should be thick and glossy.

2.) Add the egg yolks and beat until just mixed.

3.) Sift in the flour, corn starch, and salt and mix until just combined. (Try not to deflate the air in the egg whites too much).

4.) In a separate bowl, put the butter, coffee, and milk in the microwave and heat until melted. (If using oil, you don't have to put it in the microwave.)

5.) Sift in the cocoa powder, and mix.

6.) Add it to the egg white mixture until combined using the folding motion.

7.) Transfer it to the cake tin that is lined with parchment paper, and drop the filled tin on to a surface about 4-5 times to remove excess air.

8.) Put it in the oven to bake for 170 C or 350 F for 40-45 min until the centre comes out clean when a toothpick or knife is inserted.

9.) Once it is has finished baking immediately drop the cake from a height of 30 cm or 12 inches to prevent it from shrinking to much.  This will remove the excess air.

10.) Take the cake out by flipping it over and then flipping it over again.  Let it cool, and place a wet paper towel on top of the cake to prevent it from drying it out.

Peel off parchment.

Turn, it's okay if it cracks like this!

Cover with a moist paper towel to prevent it from drying out.

Now let's make the Ganache/Filling

The delicious ingredients for the frosting.

11.) Turn the burner to low heat.

12.)  In a saucepan or in a double boiler, add in the cream.

13.)  When the cream becomes warm, add in the chocolate, (and coffee if using) and stir until melted and will combined. (Don't let it boil!)

Coffee, chocolate and cream! YUM

14.)  When it is combined, remove it and transfer it to another bowl to cool down.

The warm chocolate ganache/frosting

Cut the cake!

15.) Using toothpicks as a guide, slice the cake into 3 layers.  Trim the top off to make it all flat.

I had no toothpicks, so I used Q-tips as a guide.

Cut through as a guide.

Trim off the bumpy top.

16.) Cover with a moist paper towel to prevent it from drying out.

Frost the cake! It's best to do this on a rack so that the excess frosting can drip down.

17.) Add about 2tbsp of the filling to the first layer.

Frost

18.) Put the second layer on top of the filled first layer, and do the same thing.

19.) Put the last layer on top and use the rest of the chocolate ganache/filling to frost the entire cake using an butter knife or an off set spatula.


20.) Smooth it out evenly.


21.) Put it in the fridge to harden (1 hour at least, can be overnight too!)

22.)  Can be served as is, but to make it even better, put some cocoa powder (2 tsp) in a strainer, and dust the entire cake with cocoa powder.  You can even top it with some whipped cream like I did!

23.) Transfer to a presentable plate and serve!  To slice, run the knife under warm water, then dry the blade with a towel.  Cut it.  Do this for every cut to get it nice and clean.

Hope you enjoy! Please comment below!

There you go!

Yummy ( ^ _ ^) /   　

Whipped Cream is falling off...