Preheat the oven to 375ºF. Spread the hazelnuts in an even layer on a cookie sheet and roast in preheated oven for 12-15 minutes, or untill golden and fragrant. Let nuts cool and then pour into a food processor.
Process roasted hazelnuts for 2-5 minutes, or until it becomes a loose paste. Scrape down the sides of the bowl a few times to make sure it's all combined.
Add in powdered sugar, cocoa, oil, vanilla and salt. Blend together until the mixture is smooth and glossy.
Transfer to a mason jar and store in the fridge or pantry for up to 1 month (but I bet it won't last that long...)