Chocolate icing, coarsely chopped hazelnuts and fresh mint, optional
In a large bowl, beat egg yolks and sugar until thick and lemon-colored. Stir in nuts. In another bowl, beat egg whites and salt until stiff peaks form. Fold a small amount into batter until no streaks of white remain; add remaining egg whites.
Pour into an ungreased 9-in. springform pan. Bake at 350° for 35-40 minutes or until top springs back when lightly touched. Invert pan; cool completely.
Just before serving, remove sides of pan. If desired, drizzle with icing, sprinkle with nuts and garnish with mint.