1. Combine all the dry ingredients in a large bowl, stir together to combine.
2. In the bowl of an electric stand mixer combine the vegetable oil, white sugar, light brown sugar, vanilla and eggs. Beat until well combined.
3. With the mixer on low, add the flour mixture until just incorporated. Stir in the apples and walnuts until just combined.
4. Pour the cake batter into prepared pan, smooth to edges of pan. Bake at 325 degrees for 45 - 50 minutes or until tests done with a toothpick. Cool on a wire rack.