Some possible brands:
Baratti & Milano, Venchi, and Caffarel. They all have hazelnut percentages above 40 percent, and are all made in Piedmont, where the greatest hazelnuts in the world are grown.
Crema Novi is the ultimate gianduja spread, made by a commercial chocolate producer based in Novi Ligure. Crema Novi is a plastic-tub brand found in Piemontese supermarkets, priced like Nutella but with a whopping 45 percent hazelnut content