Oat bran flour instead of oat flour
I've been substituting ground oat bran for flour for muffins, waffles, and muffins for as long as I can remember, when I am on a diet or a family member is. I have noticed the results to be a tad drier than with regular flour, so i just add a splash (maybe a tablespoon) more liquid (water or milk) depending on what I am doing. I hope that answers your question.