1. Allow butter and eggs to stand at room temperature for 30 minutes. Meanwhile, grease and flour a 10 inch tube pan. In a medium bowl, stir together flour, baking powder, baking soda and salt; set aside.
2. Preheat oven to 350°. In a large mixing bowl, beat butter with electric mixer about 30 seconds. Add sugar and vanilla; beat until fluffy. Add eggs one at a time, beating on low to medium speed 1 minute after each addition until just combined. Reserve 2 cups batter. Pour remaining batter into prepared pan.
3. In a bowl, stir together reserved batter and chocolate syrup. Pour batter over vanilla batter in pan. Dot Not Mix.
4. Bake about 50 minutes or until a toothpick inserted near center comes out clean. Cool 15 minutes on a wire rack. Remove cake from pan. Cool thoroughly on wire rack. Drizzle cake with semi-sweet chocolate icing.
