Step 1: Preheat your oven to 350°F (175°C) and line a large baking sheet with parchment paper or a silicone baking mat.
Step 2: In a large mixing bowl, using an electric mixer, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy, about 2-3 minutes.
Step 3: Beat in the large egg, mashed ripe bananas, and vanilla extract until well combined and smooth.
Step 4: In a separate medium bowl, whisk together the all-purpose flour, baking soda, ground cinnamon, and salt.
Step 5: Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix the dough.
Step 6: If desired, gently fold in the chocolate chips or chopped nuts until evenly distributed.
Step 7: Using a cookie scoop or two tablespoons, drop rounded balls of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Step 8: Bake for 10-12 minutes, or until the edges are lightly golden and the centers are set. The cookies will be very soft when they first come out of the oven.
Step 9: Remove the baking sheet from the oven and let the cookies cool on the sheet for 5 minutes before carefully transferring them to a wire rack to cool completely. Enjoy!