In a large bowl, combine sugar and oil and cinnamon and pumpkin pie spice until blended.
Add eggs, one at a time, beating well after each addition (this makes the bread fluffier).
Add in sour cream and mix well.
In a separate bowl, combine flours, baking soda, and salt.
Combine the two a little at a time, beating well after each addition.
Transfer to a greased bundt pan
Bake at 350 degrees for 60-65 minutes or until toothpick inserted near the center comes out clean.
Cool for 10 minutes in pan.
Invert onto a wire rack. Remove from pan and cool completely.
Sprinkle powdered sugar or confectioners sugar on top, slice and serve.