There really isn't a backstory to this recipe, with the exception of me wanting a healthy breakfast choice for my family since I make muffins at least twice a week. So this post will be short & sweet.
I'm not even sure where I got the original recipe, as I've been using which ever one I found and tweeking it for years. I have added bananas and fresh/frozen berries to this recipe and it always comes out great.
You can easily substitute whole wheat flour (I often do, or at least substitute half whole wheat/half all purpose). But note, you will need some additional liquid (either another splash of orange juice or a little milk.)