Preheat the oven to 275 degrees.  Line 2 baking sheets with parchment paper. Beat the egg whites and salt in a bowl with an electric mixer with the whisk attachment until foamy. Continue beating, adding the sugar gradually, until all of the sugar is incorporated and the egg whites hold stiff and shiny peaks. Scrape the beaten whites into a wide, heavy saucepan and set over medium-low heat. Stir in the hazelnuts and cook, stirring constantly, until the batter comes away from the sides of the pan and is light golden brown, about 20 minutes.  (The batter will deflate quite a bit as it cooks)  Remove the pan from the heat. Drop the batter by rounded teaspoonfuls onto the prepared pans. Bake until golden brown and firm to the touch, about 30 minutes. Remove and cool completely before serving. Store at room temperature in an airtight container for up to 1 week.