Step: 5
Let it cool and set aside in the refrigerator, stirring from time to time. The ganache is ready when it has the consistency of a spread.
Step: 6
Let’s move on to the rolled biscuit. Preheat the oven to 180°C.
Step: 7
Separate the whites from the yolks. Whisk the yolks with the sugar until the mixture whitens. Whisk the whites until stiff and add them to the mixture. To be sure not to break them, add them in 3 times: first a small part that you will mistreat a little to loosen the dough, then the rest in two times, going more gently, always with the whisk. Don’t hesitate to watch the video if in doubt.
Step: 8
Then add the sifted flour and hazelnut powder (this is important). Gently incorporate them, again with the whisk.
Step: 9
Pour the dough onto a rectangular baking sheet lined with baking paper. Smooth with a spatula and bake for 10 minutes. I advise you to monitor the cooking closely because it can vary depending on the oven over such a short period of time. The biscuit is cooked when it is colored and the top no longer sticks to your finger.
Step: 10
As soon as it comes out of the oven, turn the sheet over onto a damp cloth (I ran mine completely under water and then wrung it out well). This is important because it will allow you to roll your log without breaking the biscuit. Roll the cake up immediately in the cloth and leave to cool for about ten minutes.