Fresh Apple Cake

Preheat oven to 325 degrees F. Coat 10-inch tube pan with removable bottom with nonstick cooking spray with flour. Place walnuts in 15 1/2" by 10 1/2" jelly-roll pan; toast in oven 7 minutes or until golden and fragrant. Cool completely in pan on wire rack. Meanwhile, in large bowl, whisk flour, baking soda, and salt. In another large bowl, combine walnuts, vanilla, cinnamon, and 3 cups apples. Reserve remaining 1/2 cup apple. In large bowl, with mixer on medium-high speed, beat granulated sugar, oil, and eggs until well blended. With mixer on low speed, gradually add flour mixture, scraping bowl occasionally with rubber spatula. Beat 1 minute longer or until well combined. With spatula, fold in apple mixture (batter will be thick). Spoon batter into prepared pan. Scatter remaining apple over top of batter; with fingers, press into top of batter. Bake 1 1/2 hours or until toothpick inserted comes out clean. Cool in pan on wire rack until completely cooled. Unmold cake and transfer to cake plate. Dust cake lightly with confectioners' sugar to serve.