If using raw hazelnuts, you will need to roast them. Start by preheating the oven to 400 degrees and placing the hazelnuts on a cookie sheet lined with parchment paper. Bake for 6-8 minutes or until lightly brown.
With a towel, gently rub the hazelnuts to remove the skin.
Place the hazelnuts in a food processor or high speed blender and blend until it creates a butter like consistency. Stopping periodically to scrape down the sides.
Then add the remaining ingredients besides the oil or milk. this process will be a start and stop of blending, scraping down the sides until you get a smooth, creamy texture.
Then slowly add in the oil or milk and blend until it is extra creamy.
Store in an airtight container - if using oil, can remain shelf stable for up to two weeks or in the refrigerator for a month. If using milk, must be refrigerated.