Separate the egg whites from the yolks and whip them until stiff. Now, gradually add fine white sugar while continuing to whip on medium-low speed. Finally add the egg yolks, always one at a time, continuing to whisk.
Sift flour and dark cocoa powder into the egg mixture. Mix gently with a spatula, spoon or kitchen whisk to mix the ingredients well. Do not use the mixer but slow movements from bottom to top until all the ingredients are blended.
Line the bottom and edge of an 18-20 cm diameter cake pan with baking paper. Line the edges of the cake pan with baking paper, allowing it to protrude a little from the mould, in this way it will be able to contain the batter during baking when it grows. Pour the mixture into the pan and level it.
Bake in the static oven at 160 – 170ºC for approximately 35 – 40 minutes or until a toothpick inserted into the center of the sponge cake comes out clean. Once baked, remove from the oven and let cool before removing from the pan. Flip over and remove the baking paper and leave to cool completely.
Nutella and mascarpone cream
Place the whipping cream and mascarpone (both cold) in a bowl. Beat with the whisk at medium-high speed until all the ingredients are combined. The cream will go from a rather liquid state to a thick, whipped state. When the cream is whipped but smooth, turn off the mixer.
Now change the mixer whisks and put the spiral ones to mix. If you don't have that type of whisk available you can simply use a spoon or a silicone spatula. Add the Nutella and whisk calmly until all the ingredients are well blended.
Chocolate syrup
In a saucepan mix all the ingredients. Bring to the boil until all the ingredients are well blended. Turn off the heat and let it cool down completely.
Cake assemble
Cut the cake into 3 equal parts. Wet the first disc of the cake with a third of the chocolate syrup. Cover with a part of the prepared cream. You must divide the cream so that it remains both for the filling and for the walls and decorations with the piping bag.
Wet and fill the second and third layers in the same way, then cover the cake entirely with the cream.
Smooth the cream and create decorations as desired. I used a half-moon cake spatula to create the decoration on the side.
Place the cake in the refrigerator while you prepare the ganache. Heat the cream in a small saucepan. Add the chopped dark chocolate and stir until it melts completely. Wait until the ganache is barely warm. Cover the cake with the prepared ganache and spread it along the edge to create a dripping effect. Once completely cold, use the remaining mascarpone and Nutella cream and a piping bag to make some decorations on top.
Decorate the side of the cake as desired with halved hazelnuts. Also divide the waffers with chocolate filling into smaller pieces and use them to decorate the top of the cake. Before serving the cake, let it rest in the refrigerator for at least 1 hour.
Note from the author of this recipe
I just want to tell you that I really appreciate that you have decided to prepare my recipe. If you like it, I would be very happy and it could be a huge help for me if you follow me on my official social channel such as instagram where I publish every time a new recipe comes out. To become my follower just search for foodohfood in your instagram or click on this link: https://www.instagram.com/foodohfood/ and press Follow. Thank you from the bottom of my heart, Barbara. ^_^
Notes
The nutritional values are generated automatically for indicative purposes only and are therefore not completely accurate.