1. Beat egg yolks with 3/4 cup sugar in bowl with whisk 3 to 5 minutes or until light-colored and well beaten. Add orange and lemon zest and set aside.
2. Combine flour and salt. Add bit by bit to sugar-egg mixture, beating continually until incorporated. Add Sauternes and olive oil in increments.
3. Beat all 7 egg whites until stiff peaks form. Fold into egg-yolk mixture.
4. Grease 8-inch spring form pan and line with parchment paper. Grease again and pour batter into pan. Bake at 375 degrees 20 minutes, rotating cake if necessary to ensure even cooking.
5. Reduce heat to 325 degrees and bake 20 minutes longer. Turn off heat, cover cake with round of buttered parchment and leave in closed oven 10 minutes while cake deflates like fallen souffle.
6. Remove cake from oven and invert onto flat surface. Remove spring form pan and allow to cool completely. Cake may be stored, well sealed, in refrigerator.