Spread out nuts in a single layer on a baking sheet. Bake for 6-7 minutes, being careful not to burn.*
Let cool a few minutes, then combine all ingredients in a high-powered food processor or blender. Process on high until smooth, scraping down the sides as necessary.**
Store in an airtight jar at room temperature for about a week, or in the fridge for longer.
Notes
*Alternatively, buy dry roasted nuts. If they're salted, then omit the salt here. **It took about 5 minutes for mine to become crumbly and begin letting out the natural oils. The processing should take about 12-15 minutes, until it's smooth and liquidy.
Recipe by Lenses and Lentils at https://lensesandlentils.com/chocolate-hazelnut-cashew-butter/