Skytte's Kitchen: Valentine Chocolate Cake

Valentine... chocolate, romance, and some more chocolate.... here's how I plan to seduce.
Ingredients:
Sponge cake:
3 eggs, separated in whites and yolk
40g of dark chocolate
65g caster sugar
1 tbsp cocoa powder
Filling:
150 dark chocolate
250g mascarpone cheese
1 tsp instant coffee
1 banana
Icing:
100 g dark chocolate
1 dl cream
1 tsp instant coffee
1 tsp butter

Prepare the ingredients for the sponge cake.

Beat the egg whites until they become white and stiff. Make sure they are not too cold (whipping cream should be very cold, egg whites should not) and that the bowl and equipment are totally clean. A little amount of grease and you won't be able to make the whites stiff. Be careful not to over-whip as well. Set aside.

Beat the yolks and caster suger until white.

Add the cocoa powder.

Melt the chocolate and add it. It shouldn't be too hot, but not too cold either. Quickly whisk it in before it hardens.

Finally, turn a bit of the beaten egg whites in order to lighten it. Then a bit more and a bit more. Don't over stir it. It should be light and airy.

Grease your form very well. I just happened to have a heart shaped one. You can always make a bigger portion, bake it and then cut it out in a heart shape later.

Pour in the dough.

Bake at 180ºC for 20 minutes. When you take it out it will probably deflate a bit. That's normal.

For the filling. Melt the chocolate, add the coffee.

Make sure the mascarpone cheese is room temperature before you mix it in or it will solidify the chocolate and you'll have a lumpy mess. Should it happen, you can always heat it very carefully in a microwave to dissolve it and then let it cool down.

Once the base is cooled down, cut it through with a serated knife and carefully lift the top part off.

Slice the banana and spread it over the base.

Spread the filling over the banana. Leave a centimetre at the edges, so that when you put the top part on and apply a little preasure, it won't run out.

Carefully put the top part back on.

For the icing, mix the cream and the finely chopped chocolate and heat it carefulle in the microwave or over bain-marie. Stir to dissolve the chocolate.