Preheat the oven to 350°F (175°C) and line baking sheets with parchment paper.
In a large bowl, beat the softened butter, granulated sugar, and brown sugar until light and fluffy, about 3 minutes.
Add the egg, mashed bananas, and vanilla extract, mixing until smooth.
In another bowl, whisk together the flour, cinnamon, baking soda, baking powder, and salt.
Gradually mix the dry ingredients into the wet ingredients until just combined. Avoid overmixing.
Scoop about 2 tablespoons of dough for each cookie and place them on the prepared baking sheets, leaving space between them.
Bake the Banana Bread Cookies for 10–12 minutes, or until the edges are lightly golden and the tops appear set.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack.