Soak the hazelnuts in water overnight, then drain and rinse well.
Put hazelnuts in a high speed blender or food processor and blend until smooth, then add salt and pulse to combine. Add cacao starting with ½ cup – adding more if desired (it can be quite bitter so add little bits at a time to get desired taste) and coconut oil and blend to combine. If necessary scrape down sides of the jar. Add rice malt syrup and blend to form a paste. If by any chance the mixture separates, add warm water, 1 tablespoon at a time, while blender is running to bring the mixture back together.
Place the Nutella in a jar and store in a refrigerator for two weeks.
Serve with apple slices as a snack.