The main objective is to turn the hazelnuts into a creamy and smooth material, but it cannot be done unless you remove the skins from the nuts. Since the nuts are dry and a little hard and fibrous, it is not possible to make a smooth material without removing the skin.
The easiest way of removing the skin is toasting the hazelnuts. Place your nuts on a baking sheet and put the sheet in the oven for 10-15 minutes.
Transfer the toasted nuts to a clean and neat towel, making sure they are still hot. After properly wrapping the nuts, it is the time to wiggle them around. The nuts will grind against each other and as a result, their skin will automatically be removed. You need to do it smoothly for a couple of minutes.
Open the pack and you will find your nuts entirely naked. Separate the ones that are still not naked and remove their skins one by one.
Carefully remove the nuts from the pack, making sure you leave the skins behind. Now you have a handy amount of naked hazelnuts. Although the skins contain plenty of nutrients, it is not possible to make a delicious butter in their presence.
Once the skins are gone, you are required to process them. Put all the nuts in the food processor/blender, and process for 07-10 minutes. You are supposed to continue until you get a luscious, creamy and velvety material. If there is not enough moisture, add a little plain butter. There is no need to add even a drop of water, because the natural oil inside the nuts will itself turn them creamy.
Transfer the material to a clean jar. Mason Jars are highly recommended in this regard. Put the jar in the refrigerator for a couple of hours before serving.