Preheat the oven to 400 degrees and spray a 12-cup muffin tin with cooking spray.

In the jar of your blender, add the oats. Add the lid and process until the oats look like flour, 1-3 minutes.

Peel and add the bananas, eggs, Greek yogurt, maple syrup, baking powder, baking soda, vanilla, salt, and cinnamon to the jar of the blender and blend until smooth, 30 seconds to 2 minutes.

Add chocolate chips, if using, and stir with a spoon or spatula to combine (don’t blend).

Pour banana muffin batter into the prepared pans. Top with a few additional chocolate chips if you’d like.

Bake until the muffins spring back slightly when touched and toothpick inserted into the center comes out clean, about 15 minutes.

Let cool slightly and then remove from the pan. Serve right away or at room temperature. Store extras in an air-tight container for up to 3 days or freeze for longer storage.