In a medium bowl, combine the flour, cinnamon, nutmeg, baking soda, baking powder, and salt. Whisk together and set aside.
With an electric mixer beat sugar and canola oil until well blended. Add eggs, one at a time, beating well after each addition. Add the sweet potatoes and buttermilk and mix until incorporated. Slowly add the dry ingredients and mix by hand just until blended.
Pour batter into a greased loaf pan and bake at 350°F for 50 to 60 minutes or until when tested with a toothpick the toothpick comes out clean.
Cool on a wire rack until completely cool. Store in an airtight container.
Serve with pineapple butter, if desired.
