Add hazelnuts to a baking tray and bake in the oven for 8 minutes. They should smell fragrant and lightly toasted when nearing done.
Remove tray from the oven and tip hazelnuts onto a clean tea towel. Fold tea towel in half over and vigorously rub hazelnuts - this should remove most of the skin! If a little bit is left, that's okay.
Make bliss balls
Add the ¼ cup hazelnuts to a food processor and blitz until ground. Remove and place into a small bowl.
Add the chocolate to the food processor. Blitz for about 10 seconds - you want there to still be some chocolate chunks. Remove and place chocolate into a small bowl.
Add the remaining hazelnuts (1 cup), dates, and cocoa or cacao powder to the food processor. Blitz for around 1 minute. Add dark chocolate and water. Blitz again for around 10 seconds - don't leave the food processor running for too long as you want the chocolate incorporated, but still chunky!
Roll tablespoons of the mixture into balls. Roll each ball in ground hazelnuts. Enjoy.