Chocolate Truffle Cake

   2/3 cup cocoa 1 cup plus 1 Tbs sugar 3/4 cup *Olive Oil  (see choices below) 1 Tbs flour or cornstarch 2 tsp vanilla extract 4 eggs,  separated About 3 cups mixed berries 2 - 3 Tbs Crystal City Raspberry, Strawberry, or Espresso Balsamic Vinegar Whipped Cream (optional)   Heat oven to 400 degrees.  Oil the bottom and sides of a 9 inch cake pan.  Place a round of parchment paper in the bottom of cake pan, lightly oil the parchment. On medium heat, c...