Preheat oven to 350°F (175°C) and line a muffin pan with paper liners.
Mash bananas in a large bowl until mostly smooth.
Add eggs, oil (or applesauce), honey, vanilla, and milk. Mix well.
Add oats, flour, baking powder, baking soda, cinnamon, and salt. Stir until just combined.
Fold in chocolate chips or nuts if using.
Divide batter into muffin cups (fill ¾ full).
Bake for 18–22 minutes, until a toothpick comes out clean.
Cool for 10 minutes, then serve.