Place the hazelnuts into the bowl of a food processor and process on high speed for about 2 minutes until the nuts are completely broken down.
Add in the rest of the ingredients and process for a further two minutes until as smooth as possible. You'll probably need to wipe the inside of the bowl down with a spatula to make sure all the ingredients are well combined.
Notes
If you want your homemade healthy Nutella to be smoother, try adding an extra teaspoon of olive oil and processing for an extra minute.