Our Favorite Sour Cream Coffeecake

1/2 cup (1 stick) butter or margarine

1 cup sugar

2 egg s

2 cups King Arthur Unbleached All-Purpose Flour

1 teaspoon baking powder

1 teaspoon baking soda

1/2 teaspoon salt

1 cup sour cream or yogurt*

Feel free to use low-fat (NOT nonfat) sour cream or yogurt; if using yogurt, try vanilla or another complementary flavor, if desired.

Topping

1/2 cup sugar

2 teaspoons cinnamon

2 teaspoons vanilla

1/2 cup chopped walnut s