Combine chopped nuts with the 1/4 cup of sugar and cinnamon; set aside.
Blend together the flour, baking powder and baking soda; set aside.
Cream butter with 1 cup of sugar until light and fluffy.
Add eggs and vanilla; beat well.
Add dry ingredients and sour cream; beat until well blended (do not overbeat).
Pour half batter into greased and lightly floured 9- inch square pan; top with half of cinnamon-nut mixture.Cover with remaining batter;
top with remaining cinnamon mixture.
Bake at 375* for 30 to 35 min. or until golden brown.
Makes 1 cake
cut into 6 large squares or 6 small squares.