Preheat oven to 350 degrees F. Line a baking sheet with parchment paper or a silicone mat.
Blend 1/2 cup of rolled oats in a high speed blender or food processor until it resembles a course flour.
In a large bowl, mash bananas and add the peanut butter. Stir until well combined. Then add the oat flour from the blender and the rest of the rolled oats (3/4 cup). Stir until well combined. Fold in any optional mix ins if you want.
Scoop dough into cookies onto the baking sheet. Bake for 12-13 minutes. Don’t over bake! Let it cool on the pan for 10 minutes. Then transfer cookies to a cooling rack to cool completely. Store in an airtight container on the counter for 3-4 days. Enjoy!