Preheat oven to 375° F. Spread the hazelnuts on a baking sheet and roast for 12 to 15 minutes, until fragrant.
Carefully put the hot hazelnuts in a mason jar with the lid on and shake. The papery skins will fall right off. Remove the nuts that are now skinless and put them in a food processor or a high-powered blender, then re-shake the jar until the rest of the skins come off as well.
Grind the hazelnuts for about 5 minutes until they turn into a creamy hazelnut butter.
Add the sugar or other sweetener, cocoa powder, coconut oil, vanilla, and salt. Blend for another minute until all the ingredients are combined smooth.
Transfer to a pint mason jar. Store in the refrigerator for several weeks.
Feel free to use any sweetener you'd like in this recipe, just sweeten to taste.