To toast hazelnuts, place them on a parchment lined baking sheet in a single layer. Bake in the oven at 350 degrees for 10 to 15 minutes. Stir/Move the hazelnuts around occasionally so that they toast on all sides. Once done, use a clean kitchen towel to wrap the nuts and let steam for 1 minute. You can also use the towel to rub off some of the flaky shells. You can leave the rest of the shells.