Case study, Nutella supposedly is made up of:

55%	sugar
16%	oil
13%	hazelnut
7.8%	milk
7.4%	cocao power

Low carb alternative could be:

8oz		low carb chocolate
16oz		hazelnut
8oz		ghee
3oz		butter power
8oz		cocoa power
12oz		allulose or erythritol (maybe a little stevia to taste)
12g		lecithin
2-5g		dry or oil-based vanilla flavor, pinch vanillin

You can not add any water or alcohol based liquids (like vanilla extract) to this or it will seize!

I normally lightly roast the hazelnuts to dry out any water and bring out the flavor.

A malanger is a must to grind down everything. Make sure all the ingredients are in a molten form if possible.