Preheat oven to 350 degrees Fahrenheit. Grease and prepare a bundt ban.
In a large bowl, whisk together flour, xanthan gum (if using), baking soda, baking powder, salt and cinnamon.
In a medium bowl, mix together vegetable oil, eggs, sugar, and vanilla extract.
Peel and core pear and then shred them (or dice finely). You will need 2 cups of the pears.
Add the pears to the wet mixture. Mix until well combined.
Pour the pear/wet mixture into the flour mixture.
Stir until there are no more streaks of flour in the batter.
Pour batter into the bundt pan.
Bake for 50 minutes, or until an inserted toothpick comes out clean.
Cool on a wire rack for 10 minutes and then carefully flip the bundt pan over to release the bread. Sprinkle with powdered sugar to serve.