Put the gelatin sheets into a bowl of cold water and let them soak while you heat the cream.
Combine the heavy cream and chocolate hazelnut spread in a medium saucepan and put it over medium-high heat. Bring it to a boil and then remove it from the heat. Squeeze the excess water out of the gelatin and add it to the warm cream. Stir well to make sure the gelatin is dissolved. Pour the mixture into small bowls and refrigerate, covered, overnight or at least 4 hours.
When you are ready to serve, garnish with the chopped hazelnuts and grated chocolate. Sweet!