Preheat the oven to 350 degrees F (180 degrees C).
Chop the Walnut (1/4 cup) and roughly chop the Old Fashioned Rolled Oats (1 cup). This will help the cookies to hold together more easily.
Combine the Banana (2), rolled oats, walnuts, Ground Cinnamon (1/2 teaspoon), and Vanilla Extract (1/4 teaspoon) in a bowl. Use a fork or potato masher to mix everything together. If the batter seems too dry, add some more banana, or if it’s too wet, add some more oatmeal.
Form the mixture into balls and place on a greased cookie sheet. Bake for 15 or so minutes.