Preheat the oven to 350°F (177°C). Line a baking sheet with parchment paper. In a large bowl, mash the bananas with a fork until they're smooth and pureed.
Add the oats and stir until the mixture is well combined.
Add the chocolate chips or your favorite mix-ins, then stir again.
Drop 1 ½ tablespoon portions of dough onto the baking sheet (I love to use this cookie scoop), then use your fingers to flatten them into a round cookie shape.
Bake the banana oatmeal cookies for 13 to 15 minutes. Remove from the oven, let cool for a few minutes, then enjoy.
