First, preheat the oven to 350F and line a larger baking sheet with parchment paper or a reusable baking mat.
Next, in a high-speed blender or food processor, blend one cup of the rolled oats into a flour-like consistency and set aside.
In a larger mixing bowl, mash the bananas with a fork until they are mostly smooth with a few chunks. Add in the rolled oat flour, the rest of the rolled oats, baking soda, cinnamon, maple syrup, and salt. (Everything but the raisins.) Mix until thoroughly combined.
Next, fold in the raisins into the cookie dough.
Scoop out 1-2 tablespoons per cookie and form into a ball. Place each cookie onto the prepared baking sheet.
Place in the oven and bake until the oatmeal raisin cookies are lightly golden brown and/or just barely set when touched. Approximately 15-20 minutes. Remove from oven and cool for at least 10 minutes.
Want flatter cookies? Just press each ball down slightly before you bake the cookies and reduce the baking time by 1-2 minutes.