Preheat oven to 375 degrees. Cream together butter and sugar. Add eggs, one at a time. Sift dry ingredients and add alternately with sour cream. Pour into greased and floured 8 x 12 pan. Pour syrup over and swirl with knife. Sprinkle cinnamon, sugar and nuts onto mixture. Bake for 35 minutes at 375 or until a toothpick comes out clean. Cool and serve.