Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy.
Add the mashed bananas, egg, and vanilla extract to the butter mixture, and mix until well combined.
In a separate bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
If using, fold in the chopped nuts and chocolate chips.
Drop rounded tablespoons of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake for 10-12 minutes, or until the edges are lightly golden.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.