Toast hazelnuts on a cookie sheet in a 350-degree oven for 8-10 minutes. Cool. When cool rub the hazelnuts to remove their skins.
Add nuts to a food processor or blender/Vitamix. Pulse until nuts are very small pieces. Add remaining ingredients, starting with just some of the water. Blend well. Add water as necessary to reach the desired consistency. Scrape down sides or use a tamper to ensure the mixture is well blended.
Eat right away or keep in the refrigerator for up to 5 days.