Peanut butter banana oatmeal cookies are easy, healthy, and flourless! This 3 ingredient cookie recipe requires rolled oats, bananas, and peanut butter. Add your choice of mix-ins, like chocolate chips and cinnamon. They are vegan, gluten-free, oil-free, and refined sugar-free. This wholesome treat can act as breakfast cookies, a midday snack, or for a nutritious dessert!