I was wondering what is the appropriate brocha for the following item.
Instant oatmeal (whole oats) are mixed together with mashed bananas and are then baked forming a cookie. The oats stick closely together due to the stickiness of the banana.
There is nothing else added to the mixture. Soy bean oil spray is sprayed on the tray to prevent sticking.
Also would this mixture require hafrashas challah if large batches are made?
This is a very interesting question. You should make a mezonos on the cookies. This is in part because there is water content in the banana, that will be bringing out the gluten of the oatmeal, and in part because when a person is in doubt, they can say mezonos as the Chayei Adam says.
Regarding taking challah, you don’t have to take off challah because there isn’t any of the 7 liquids in the mixture, and because it isn’t really a dough.