Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper or a silicone baking mat.
In a mixing bowl, cream together the softened butter, brown sugar, and granulated sugar using an electric mixer or whisk until the mixture is light and fluffy.
Add in the mashed bananas, egg, and vanilla extract to the butter and sugar mixture. Mix well until all ingredients are combined.
In a separate bowl, whisk together the all-purpose flour, baking soda, baking powder, salt, and ground cinnamon.
Gradually add the dry ingredients to the banana mixture, mixing until just combined. Be careful not to overmix.
If desired, fold in the chocolate chips and/or chopped nuts.
Use a cookie scoop or tablespoon to drop dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake in the preheated oven for 10-12 minutes or until the edges are lightly golden and the center is set.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.