For cake: Boil syrup exactly 2 minutes. Beat egg whites until stiff and set aside. Beat egg yolks and vanilla until light, then gradually mix in boiled syrup.
Fold egg yolk mixture gently into egg whites. Sift remaining dry ingredients together 3 times and fold into egg mixture. Pour batter into an ungreased 9 or 25 cm tube pan. Bake at 160ºC for 50 minutes, or until done. When cake is cooked, invert pan on a cake rack and let cool for 1 hour. To unmould, pass a knife around the edges and ease cake out of the pan.
To make icing, boil syrup until it forms a firm ball when tested in ice water (328 degrees F on candy thermometer). Beat egg whites until stiff, then slowly pour hot syrup on top, beating constantly with an electric beater. If you use a hand rotary beater, pour in a little syrup, beat, pour more, beat until all syrup is used. Continue beating until frosting stands in peaks, or cools. Spread on top and sides of cake.