preheat oven to 375°. Grease and flour a 10 inch fluted tube pan; set aside. In medium bowl stir together flour, baking powder, baking soda, and salt; set aside.
In large mixing bowl beat sugar and oil with an electric mixer on medium speed for one minute. Add eggs, one at a time, beating well after each addition. Alternately add flour mixture and buttermilk, beating on low speed after each addition just until combined. Beat in the two third cup chocolate syrup and vanilla. Pour batter into the prepared pan.
Bake for 1 1/4 to 1 1/2 hours or until a wooden toothpick inserted in center comes out clean. Cool in pan on wire rack for 15 minutes. Remove cake from pan; cool completely on rack. Transfer cake to serving plate; drizzle with chocolate cream drizzle. Just before serving, drizzle the 2 tablespoons chocolate syrup around top edge. Makes 12 to 16 servings.
Chocolate cream drizzle: in a medium bowl whisk together 1 1/2 cups powdered sugar, 2 tablespoons chocolate syrup, and 2 tablespoons milk. If needed, whisk in milk, 1 teaspoon at a time, to make drizzling consistency.