PREHEAT oven to 350°F. Place cake mix, dry pudding mix, soda, oil and eggs in large bowl. Beat with electric mixer on low speed just until moistened. Beat on medium speed 2 minutes, scraping side of bowl occasionally. Gently stir in walnuts.
POUR batter into greased and floured fluted tube pan or 10-inch tube pan.
BAKE 40 to 45 minutes or until toothpick inserted near center comes out clean. Cool in pan 10 minutes. Remove cake from pan; cool completely on wire rack. Sprinkle with powdered sugar just before serving.