Peel and roast the hazelnuts if it hasn't been done yet. Hazelnuts need about 15 minutes in a 350°F / 180°C preheated oven.
In a food processor chop the hazelnuts as finely as possible. Grind them with a grinder if there is one available.
Melt chocolate.
Pour melted chocolate into the ground hazelnut.
Give it another whirl and we are about to finish with our hazelnut spread.
Add vanilla and salt then mix it again. Mind to put small amounts of salt in there as even as little as a ¼ teaspoon can across quite harsh.
Add a bit of oil if the spread seems too thick then mix it a bit more. Mind not to use Extra virgin olive oil or any other with a characteristic flavor. Also add sweetener to taste if necessary. If we melted chocolate that was already sweetened then additional sweeteners shouldn't be necessary. Except of course if we are shooting at making nutella because in that case we need at least as much sweetener as everything else in our spread.
Our chocolate hazelnut spread should be ready to roll or rather spread.
Fill it in jars, cups or anything that has an airtight lid. It doesn't need refrigeration but keep it in a dark cool place if possible.