Combine cake mix, pudding mix, eggs, sour cream, oil and Kahlua in large mixer bowl. Blend well; then beat at medium speed for 4 minutes. Stir in nuts and/or chocolate chips. Pour into greased and floured 10-inch tube or Bundt pan. Bake at 350 degree for 50 to 55 minutes or until cake tester inserted in center comes out clean and cake begins to pull away from sides of pan. Cool in pan 15 minutes. Remove from pan and finish cooling on rack. When cool - frost if desired - or sprinkle with powdered sugar.