Preheat oven to 350 degrees. Cream butter, white and brown sugars in mixer bowl until light and fluffy. Add flour, cinnamon and salt; mix well. Reserve 1 cup of mixture for topping.
Combine sour cream, eggs and soda in small bowl. Add to creamed mixture; mix well.
Sprinkle greased 8-inch square pan with pecans. Spoon batter over top. Sprinkle with reserved topping. Bake at 350 degrees for 35 minutes. Makes 9 to 12 servings.