In small dish, combine granulated sugar, brown sugar, walnuts, cinnamon and salt.
Sift flour, baking powder, baking soda and salt onto piece of wax paper. Set aside.
Use mixer to cream sugar and butter until fluffy.
Add eggs 1 at a time, beating well between addition
Then vanilla extract and sour cream.
Add four mixture. Mix will.
Transfer ½ of batter to buttered and floured 9 inch square baking pan. Spread in thin aver. Sprinkle ½ of topping over batter. Repeat with remaining batter and topping.
Bake at 325º until lightly browned and toothpick inserted in center comes out clean, about 40 minutes. Cool on wire rack. Cut into 16 small squares.