Preheat oven to 350°F (175°C) and roast hazelnuts on a baking sheet for 10 minutes until skins are slightly blistered.

Transfer warm hazelnuts to a clean kitchen towel and rub vigorously to remove the bitter brown skins.

Place the skinned hazelnuts in a high-speed blender or heavy-duty food processor and process for 5-8 minutes, scraping down sides, until a liquid hazelnut butter is formed.

Add the sifted powdered sugar, cocoa powder, vanilla extract, and salt to the processor.

Continue processing on high while slowly drizzling in the neutral oil until the mixture reaches a smooth, glossy, and emulsified state.

Transfer the spread into a glass jar and allow to sit at room temperature for 2 hours to set before use.