Preparation:
Preheat oven to 160 degrees.
Thoroughly grease a 12 cup Bundt pan.
In a medium bowl combine the flour, baking soda, baking powder, cinnamon, and salt.
In a large mixing bowl combine the sweet potatoes, oil, and sugar.
Beat until smooth.
Add eggs two at a time, beating well between each addition.
Add the flour mixture and beat until just blended.
Add the vanilla and mix to incorporate.
Transfer the batter to the Bundt pan.
Bake for 1 hour and 5 minutes or until a cake tester comes out mostly clean.
Cool the cake in the pan for about 15 minutes, then invert onto a cake platter.