Arrowroot is a starch derived from root vegetables and lends well to gluten free baking. Make your own gluten free flour blend at home and store in an airtight container for stellar baked goods every time.
Store in an airtight container for best results.
Check labels to ensure the oat flour you buy is 100% gluten free, as oats can sometimes be contaminated with gluten.
Note that potato starch is not the same as potato flour, though sometimes potato starch is erroneously labelled as potato flour. Make sure what you buy is a refined, white powder, as true potato flour is made from the entire potato, including the skin, and is less refined.