Preheat the oven to 350ºF/180ºC and put the hazelnuts on a baking sheet lined with baking paper. When the oven is hot, roast the hazelnuts for 8 minutes until the skins crack. Remove from the oven and allow to cool enough to handle.
Add the sugar to the blender and blend on high for 15 - 20 seconds. Or until it has an icing/powdered sugar consistency. Remove from the blender and set aside.
Lay a tea towel flat on the kitchen bench and pour the cooled hazelnuts into half of it. Fold the other half over the top and rub them vigorously until the skins slide off (see note 3).
Add the skinless hazelnuts to the blender and blend on high for 5 minutes. You want to create quite a liquid nut butter. You may need to scrape down the sides of the blender a few times before continuing.
Next add all the remaining ingredients and blend again on a medium-high speed for 5 minutes until well combined. If needed, stop the blender, and scrape down the sides a few times to ensure everything is well incorporated.
Pour into a jar and put it in the cupboard or put it in the fridge to extend the shelf life. This homemade chocolate spread will last for 2 weeks in the cupboard or up to 2 months in the fridge.