Once again I turn to surf the cake that makes the buzz right now. 
This is the bottle-shaped cake of Coca Cola. 
He had to think, it is not I who had the idea but I find it really fun ... 
the principle is simple: an empty bottle of Coca Cola to serve as a mold, chocolate, sponge cake and filling. I resumed my recipe classical Genoese, and I made ​​a chocolate mousse for garnish. 
You will find mainly cakes with a large bottle of 1.5 liter format. I used a 1 liter bottle and I adapted the proportions for this cake.

For a cake 1 liter bottle (6-8 people): for the cake : 4 eggs 120 g sugar 120 g flour 1 tablespoon baking powder

for chocolate mousse : 
3 eggs 
100 g dark chocolate

for coating : 
400 g of dark chocolate (70% half half 50% cocoa for me)

Empty the bottle of Coke. Wash and dry. Remove the label very carefully without tearing. washing to remove the glue. Cut with a knife a "window" in the bottle: a rectangle that will pass the filling into the bottle.

Prepare the chocolate mousse : 
Separate the whites from the yolks. 
Whisk the egg whites with a pinch of salt. Melt chocolate in a double boiler or in the microwave, stirring regularly. Mix the warm melted chocolate with the egg yolks. Gently fold the whites to the mixture and let stand at least an hour in the fridge. Prepare the coating: Melt chocolate (400 g) in a water bath. The ideal is to temper to make it bright and crisp and it comes off well when the plastic mold. To temper using a thermometer.(the technique is there ) which is done to the eye like me sometimes: I melt my chocolate gently while stirring. When it starts to melt well but there are still some pieces, I stop the fire and I strongly stirs to allow the remaining chocolate from melting.This will lower the temperature and may crystallize properly afterwards.

Properly wipe the bottle with paper towel or some cotton to avoid any trace. Place the plastic closure on the neck of the bottle. Pour the melted chocolate into the bottle through the hole made. 
Tilt the bottle all sides to allow top with chocolate walls. Put the bottle "hole below" over a bowl to allow excess chocolate to flow. Then put the bottle in the fridge for 30 minutes. Repeat the operation by putting one second layer of chocolate in the bottle.Drain the excess and leave the bottle still cool for 30 minutes.

Prepare the cake : 
Separate the whites from the yolks. Whisk length the yolks with sugar to let the mixture triples in volume and become frothy. Add the flour and baking powder, whisk. Then mount the egg whites with a pinch of salt. 
Incoporer whites gently into the above mixture using a rubber spatula, gently lifting the mixture. 
Pour batter on a rolled plate (silicone plate to me with flanges 30 x 40 cm) and bake at 180 ° for 10 minutes already preheated oven (8 to 12 minutes depending on oven biscuit should be lightly colored but remain soft and moist) 
Turn gently and pack in a tranfert movie or cloth wet. Mounting : Take the bottle with the hardened chocolate. Cut cookie bands 2-3 cm wide and 7 to 10 cm long and remove the bands bottom of the bottle. Coat the entire chocolate mousse. Put another layer of biscuit and cut a layer of foam. Toggle this until the bottle is filled. Finish by brushing with melted chocolate openness. Place in the refrigerator to let it harden everything. Leave overnight.

The next very delicately cut the plastic bottle using small sharp scissors, being careful not to trace in chocolate. Use latex gloves to avoid leaving fingerprints on chocolate. I cut a strip of plastic at the site of the opening and then I cut the bottom by pulling slowly to take off the plastic chocolate. I finished in the top and I pulled gently on the neck to bring the whole. 
This is tricky but doable. 
If the chocolate has white streaks or fingerprints, wipe gently with hands protected by gloves to make disappear the footsteps.

    

verdict of the chocolate family: they all made "whaouuu !!"seeing my bottle arrive on the table. The girls did not want to try because of the black chocolate (so to redo them with milk chocolate) Chocolator junior and Mr. chocolate have liked.

Aesthetically it is this extra cake. For the taste by cons is not the best 3D cake that I made. The chocolate mousse sponge cake fodder is nice and classic home but the chocolate shell is too thick and makes the less pleasant tasting. The cut is also more difficult with this thickness. 
We can not escape this inconvenience, if the chocolate layer is too thin, it could crack and release will be complicated. 
Chocolate mousse can be replaced by whipped or whipped mascarpone mousse in which one can insert fruit (raspberries, cherries, peaches ...) 
with these proportions I had just enough chocolate mousse and stayed many biscuit (almost half) if you a small plate rolled biscuit reduce the ingredients of the cake in half. You can put an egg more and 35 g of chocolate over the chocolate mousse. 
The amount of the different ingredients depend on the thickness of the cake (I advise not to do too thick and not overcook ) If you find dry, with the punchez imbibage syrup (water + sugar + perfume)

The success of this cake is linked to a good tempering chocolate to the hull. If it is mild, it will be bright and crisp and démoulera easily.

This cake requires a little time and patience, but the result is so nice that we forget the inconvenience. 
We can use a bottle of Coca Cola, Ice Tea or other soda.