1. In the small bowl of an electric mixer, beat-egg whites until foamy.
Beat in the 1/2 cup sugar, 1 tablespoon at a time, beating until stiff and glossy. Set meringue aside.
2. Place flour, the 1 cup sugar, baking powder, salt, oil, and half of the orange juice into a large, heat-resistant, non- metallic bowl. beat 1 minute at high speed, scraping sides of bowl constantly.
3. Add remaining orange juice and egg yolks; beat an additional 1 minute at high speed, scraping sides of bowl constantly.