Topping: Mix together flour, sugar, salt and nuts. Add butter in small pieces.
Rub in by hand until mixture is crumbly. Be careful not to over-mi. Set aside.
Cake: In bowl mix together flours, baking soda and baking powder.
In another bowl cream together butter with sugar until fluffy and light. Add
egg and vanilla extract and mix well. Add half of dry ingredients, mixing just until
flour is blended. Blend in sour cream, then remaining dry ingredients.
Spread half of batter lightly into a 10-inch tube pan. Sprinkle with half of
Topping and spread with remaining batter. Sprinkle with remaining Topping.