Roast the hazelnuts at 375° with the skins on for about 10 to 15 minutes.

Remove from the oven and let them cool until you are able to handle them.
Put a handful at a time in a clean tea towel or lint-free towel and rub them together until the skins come off. Shake the nuts free of the skins. They don’t have to be perfect, just most of the skins gone.

Place the nuts in the Vitamix or other high-powered blender. Start on slow and process on low to medium for a minute or so while tamping down in the corners. (This is important when you are not adding other oil)

When all of the nuts are crumb size crank up the speed to high and keep tamping down in the corners. Keep blending until smooth and creamy.

I store mine in 2 pint-sized wide-mouth mason jars to make it easy to scoop out with measuring spoons.  Keep them refrigerated to minimize separation and maintain quality.