In a heat-safe bowl over simmering hot water, melt and combine Semi-Sweet Dark Chocolate (400 gram) and Whipping Cream (2/3 cup) to make the ganache.
Place the bowl into the fridge for 10-15 minutes to chill.
On your serving plate, place one of the Crepes (24 piece) and dollop a tablespoon from the Nutella® (13 ounce). Gently spread the Nutella with the back of a spoon.
Place the second layer of crepe and repeat until you've used all of the crepes making sure the top layer of the cake doesn't have any nutella.
Spread the cooled ganache on top and over the sides of the cake. Decorate with Hazelnuts (1 handful), chill for 15-20 minutes until ready to serve.
You can make up to one day ahead and just take it out of the fridge 15 minutes before serving to soften. Slice and serve!