If you're making Nutella or something else that requires toasted and peeled hazelnuts, you usually need to remove the paper-like skins. Make them easier to remove by boiling the hazelnuts in water with bicarb soda.
Culinary blog My Baking Addiction found this tip from an old clip of Julia Child's cooking show. After boiling the hazelnuts in the water for three minutes, the water will become black. When you drain the hazelnuts and rinse them with cold water, the skins should slip off easily.
The conventional method of removing hazelnut skins is to roast them for 15 minutes at 175C and then rub the skins off with a dampened kitchen towel. The author at My Baking Addiction tried both methods and found the boiling technique to be the better method of the two.
How to Peel Hazelnuts [My Baking Addiction]