CAKE: Position rack in center of oven. Preheat to 350 degrees F. Line bottom of 10″ springform pan with foil; brush foil with oil. Cut cardboard into 9″ round and cover with foil. Using electric mixer, beat egg whites and salt in a large bowl until soft peaks form. Gradually add 1/2 c sugar and beat until stiff glossy peaks form. In another large bowl, beat egg yolks, remaining 1/2 c sugar, vegetable oil, orange juice conc…..