Cake Ferrero rocks or boulders log ferrero

This cake is in my head for over a year, I tried, tested, modified, tasted, again without finding the recipe that I liked as much visually and taste. I had to make 3 or 4 cakes before the one I propose today. 
I wanted the taste of chocolate, nutella, crunchy of Ferrero, and hazelnut. 
I used a log to mold but you can use a loaf pan or round pan with a capacity of 1.5 l. 
it is composed of a sponge cake with chocolate, a dark chocolate mousse and nutella, a thin layer of crunchy praline and it is dotted with slivers of roasted hazelnuts. It has a good performance and an easy cut.

8 people (in the mold of 1.5 log) for the chocolate mousse nutella : 6 eggs (separated white and yellow) 150 g chocolate 50 g Nutella

for the Genoese cocoa : 
3 egg yolks 
of eggs 4 white 
85 g flour 
100g caster sugar 
1 tablespoon domed soup and a tablespoon of bitter cocoa 
1 pinch salt

for crunchy praline
1/2 pralinoise tablet (85 g) 
4 bags of gavotte (lace crepes)

for glazing ; 
40 g cream, 50 g of dark chocolate 70%, 10 g butter cut 4 pieces, 55 g of chocolate sauce (35 g of dark chocolate 70% chopped, 65 ml of water, 35 g heavy cream, 15 g of sugar)

for decoration : 
20 g whole hazelnuts 
3 Ferrero rocks

Start by preparing the chocolate mousse:
Melt the chocolate in a bain marie. Add the Nutella when melted. Mix well. Separate the white of egg yolks. Mix the yolks one by one in the warm chocolate. Mount the egg whites with a pinch of salt. Fold in white chocolate using a spatula to avoid breaking the whites. Refrigerate.

prepare the crisp:
Melt pralinoise and cool. Coarsely crush the gavotte and put them in melted chocolate.Mix gently. Spread this mixture on a sheet of baking paper and leave to cool (keep two spoons to the bottom of the log not chill)

Prepare the cake : 
Preheat oven to 180 degrees. 
Beat 3 egg yolks with 100g of sugar. Whisk length until the mixture whitens. Then add the sifted flour and cocoa and whisk to mix well. 
Beat the egg whites until stiff 4 with a pinch of salt. 
Put a large spoonful of egg white into the batter and mix well to make it more flexible and when it is "relaxed" gently add the remaining whites with a spatula. 
the dough should be soft homogeneous. Spread the dough on a baking sheet covered with parchment paper or a silicone plate edges (for special rolls) I use a plate of 30 cm by 40 cm. Proceed immediately to the oven and cook at 180 degrees for 8 minutes (the biscuit must remain soft to the touch. Remove from oven and turn out onto a clean, wet cloth and wrung to gently loosen the cookie. Place plastic wrap on cookie and gently place the plate in the buche pan, making sure that the food film is against the sides of the cookie moule.Découper surplus and to keep the inner layers and the bottom of the buche.

dressage : 
Place the bottom of the log two tablespoons of crunchy praline by spreading without much support. Then spread chocolate foam layer. Cut a strip of biscuit (remains of the cake) and remove the foam. cut a crispy praline layer to the dimensions of the strip and drop cookie crispy on the biscuit. Put chocolate foam layer and end with a biscuit band.Ask cling film and leave to cool at least 4 hours. It must remain a little chocolate mousse, keep it to the finish.

Icing : 
Mix the ingredients of the chocolate sauce in a saucepan. (ie: 35 g of dark chocolate 70% chopped, 65 ml of water, 35 g of heavy cream and 15 g of sugar) Gently melt stirring. Simmer until the sauce is thickened and coats the spoon. Book. 
Make 40 then boiled cream, remove from heat add 50 g of chocolate and mix. Ensure that the mixture does not cool too quickly (if necessary put in a water bath) add the butter cut into small pieces. Mix well to smooth everything. Add 55 g of chocolate sauce previously prepared. Mix the icing is ready for use.

Finishes : 
Make roast the hazelnuts in the oven or a hot stove to dry then chop coarsely. 
Turn gently the log, remove the cling film. Cover the cake with a thin layer of chocolate mousse (the rest of the trim) If there is no more foam, put a thin layer of nutella.Sprinkle then the cake with chopped nuts (they will stick on the foam layer) 
Pour the chocolate frosting over the entire surface of the cake (it should be thick and liquid, warm it slightly if necessary to make it liquid) caught cool for two to three hours. 
Decorate with halves Ferrero rocks and eventually the gold powder or chocolate decorations.

      

    

verdict: we do not eat a ferrero, but a soft cake that has the crisp and melting. 
He had success at home. In version photographed the biscuit is too thick and you do not feel quite the foam, I propose you a more tailored version. 
The cake is easy to cut, icing is soft and crispy layer is not too thick, it is not hard to cut.

We can make a kind biscuit, confectionery, we better see the different layers of the cake (in this case remove 5 g sugar for the cake) 
Do not overcook the cake so it does not dry. 
In the photos, my cookie is a little too thick, I had put the yeast. So I dropped the dough for proportions that the biscuit is finer. 
I mounted my cake did not prepare before my crusty plate (it was difficult to spread directly on the biscuit in the buche) it is best to prepare before crispy and cut cookie format.

You can use chocolate with 50% cocoa for the foam. 
You can make a dark chocolate mousse half / half pralinoise and thus remove the nutella. 
I tried a version with a chocolate ganache and praline but it was too heavy.

you can also make a Joconde biscuit (or cookie approaching the Joconde biscuit with 2 eggs, 35 g almonds, 40g of flour, 
60g icing sugar, 2 egg whites, 1 pinch of salt, 1 to 2 drops of almond extract, 1 handful flaked almonds) 
Whisk 2 eggs with 60g icing sugar, add 35 g of almonds, 40 g of flour and 1 to 2 drops extract of bitter almond. mix well.Fit 2 egg whites with a pinch of salt in a separate bowl then add the egg whites to the above mixture by lifting gently with a spatula. Cook on a plate rolled for 8-10 minutes at 180 °

  
My previous tests: Round cake (praline mousse / chocolate) 
and cake with chocolate ganache / nutella 
(3 layers of foam and biscuits or ganache between layers)