1.
Heat oven to 325 degrees. Lightly oil a 9-inch spring form pan. In a large bowl, combine cocoa and sugar; stir until blended. Whisk in water until smooth, then whisk in extra-light olive oil, whole egg, egg white and vanilla.
2.
Combine flour, cornstarch, baking soda and salt; whisk into cocoa mixture until smooth. Pour into prepared pan. Bake 45 to 50 minutes, until toothpick inserted in center comes out clean.
3.
Cool in pan on wire rack. Loosen cake from side of pan with small spatula. Transfer, cake to serving plate and sprinkle with confectioners’ sugar. Cut in wedges and garnish with fresh raspberries, if desired.