Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a mixing bowl, mash the ripe bananas until smooth. Set aside.
In another bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy using an electric mixer or whisk.
Add the egg and vanilla extract to the butter mixture and mix until well combined.
Stir in the mashed bananas.
In a separate bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon (if using).
Gradually add the dry ingredients to the banana mixture, mixing until just combined.
Fold in the chocolate chips or nuts if desired.
Drop tablespoons of cookie dough onto the prepared baking sheet, leaving space between each cookie.
Bake in the preheated oven for 10-12 minutes or until the edges are golden.
Remove from the oven and let the cookies cool on the baking sheet for about 5 minutes before transferring to a cooling rack.