1. Beat egg whites and sugar until stiff. Set aside.
2. In small saucepan, melt margarine and chocolate.
3. Beat egg yolks and combine with melted chocolate. Gently fold in beaten egg whites.
4. Pour half of the batter into a nine-inch round pan. Bake for 20 minutes. Cool.
5. Pour second half over baked layer. Freeze for 45 minutes.
6. Beat whip cream and confectioners sugar until it forms stiff peaks. Spread over chocolate layer.
7. Garnish with grated chocolate or Viennese Crunch.
8. Preheat oven to 350 degrees Fahrenheit.