Preheat oven to 350℉.
Grease and lightly rice-flour 2 (8x4-inch) loaf pans and set them aside.
In mixing bowl beat together sugars and oil.
Add eggs and vanilla, beat until well blended.
Stir in zucchini.
In another bowl combine gluten free flour, Xanthium, salt, cinnamon, soda, and baking powder.
Add to creamed mixture and mix well.
Stir in walnuts and raisins, if desired.
Spoon the batter into the two prepared pans.
Bake for 60 minutes or until a stick inserted in the middle is done.