Chocolate Mocha Cream Roll - Sugar Free

INGREDIENTS:

1/2 c Margarine
2 oz Unsweetened chocolate
1 1/2 c Flour
1/2 ts Baking powder
1/2 ts Baking soda
1/4 ts Salt
1 c Brown sugar; packed
1/2 c Buttermilk
1 lg Egg
1 ts Vanilla
1 c Chocolate chips
1/2 c Walnuts; chopped