Firstly melt the chocolate in the microwave at medium power / low, being careful not to burn it.
When the chocolate is completely melted, add one by one the other ingredients: hazelnuts, toasted and chopped, the cocoa powder, sugar and olive oil. Be careful to use a very light oil, such as the Riviera Ligure Extra Virgin Italian Olive Oil DOP.
Mix all the ingredients and work them until the dough is firm but soft enough.
Give them the shape you wish: sprinkle some cocoa on the working area, then take a piece of dough and roll it to form a long cylinder.
Cut the roll of dough into pieces about 1.5 / 2 cm and then one by one work them with your hands to give them a more rounded shape.
Dip the obtained chocolates in the soft sweet cocoa powder, making sure to cover them completely. Give each chocolate an irregular shape, such as truffles, molding them quickly with a light finger pressure.
Then arrange them in a baking pan in a cool place, so that the cocoa powder attaches properly to the dough: leave them in a cool place for about half an hour / hour, or put them in the refrigerator for about 5 minutes.
After this time, remove the excess cocoa chocolates and arrange on a serving platter.