Heat oven to 200C/180C fan/gas 6. Tip the hazelnuts onto a large baking tray, place in the oven and roast for 10 mins, stirring now and then to ensure they don’t catch at the edges. When golden brown, remove form the oven and leave to cool completely.
Tip the nuts into a food processor, add the cocoa or cacao, maple syrup and salt. Blend for 6-8 mins, until you’re left with a smooth nut butter, if you want to loosen the consistency, add a drizzle of hazelnut oil and blend again.