To toast the hazelnuts, add them to a baking sheet in a single layer. Bake the hazelnuts in the oven preheated to 350F degrees for 10-15 minutes. If you want to remove the hazelnut skin, cover the pan with a clean kitchen towel as soon as you remove the nuts from the oven. The steam created under the towel will loosen the hazelnut skins, helping you peel them more easily.