Black and white puddings

1. Prepare vanilla pudding: in 1-quart microwave-safe bowl, combine sugar and cornstarch.
2. Stiri in milk until well blended and cornstarch is dissolved.
3. Microwave, uncovered, on high (100 percent) 2 ½ to 3 minutes, or until mixture boils and thickens, whisking after every minute.
4. Stir in egg until well blended.
5. Microwave on medium (50 percent) 30 seconds; stir in vanilla and set aside.
6. Prepare chocolate pudding as in step 1, substituting the chocolate for vanilla.
7. Stir chocolate into pudding mixture until completely melted and blended.
8. Set aside vanilla and chocolate puddings until barely warm.
9. Pour one quarter of each pudding simultaneously into each of 4 small dessert bowls.
10. With fork, swirl each pudding mixture to marbleize.
11. Refrigerate black and white puddings at least 40 minutes.
12. Garnishi with berries, if desired, and serve.