
Preheat the oven to 350°F. Spread the hazelnuts on a baking sheet and roast for 12–14 minutes until fragrant and the skins crack.
Transfer the warm hazelnuts to a clean kitchen towel. Rub them together to remove most of the skins (it's okay if a few bits remain).
Place the hazelnuts, powdered sugar, cocoa powder, oil, vanilla, and salt in a food processor. Blend until they turn into a smooth and glossy paste, stopping to scrape down the sides as needed.
Transfer to a clean jar. The spread will thicken as it cools.