1. Preheat oven to 350 degrees.
2. In a small bowl, combine the flour, baking soda and salt; set aside.
3. In a mixing bowl, cream the butter with the sugars.
4. Add the egg, banana and vanilla; beat until smooth.
5. Beat in the flour mixture.
6. Stir in the oats and chocolate chips.
7. Drop the batter by large spoonfuls 2 inches apart onto nonstick baking sheets (or line the sheets with parchment paper).
8. Bake for 10 to 14 minutes, until lightly browned and almost firm when pressed in the center.
9. Remove the entire baking sheet to a wire rack to cool for 2 to 3 minutes, then transfer the cookies to the rack to completely cool.