In a large bowl, beat sugar, oil, eggs and vanilla until well blended. In another bowl, whisk flour, cinnamon, baking soda and salt; gradually beat into sugar mixture (batter will be thick). Fold in apples. Spread into a greased and floured 13-in. x 9-in. baking pan.
For topping, beat the butter, sugar and cinnamon in a small bowl. Stir in coconut and walnuts; mix well. Sprinkle over the batter. Bake at 350° for 35-40 minutes or until a toothpick inserted in center comes out clean.