Preheat oven to 325ºF. Spray a 10 to 12 cup Bundt baking pan with nonstick baking spray containing flour.
Sift together the flours, baking soda and salt in a medium bowl.
In large mixing bowl, cream the butter and sugar on medium speed until light and fluffy.
Add the eggs one at a time, beating well after each addition. Add half the flour mixture and mix on low speed. Then add in the sour cream, pumpkin puree and vanilla extract and mix again. Add in the rest of the flour and mix until batter is smooth.
Pour the batter into the prepared pan and spread evenly. Bake for about 75 minutes or until a toothpick inserted in the center of the cake comes out clean.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.