01 - Preheat oven to 350°F. Grease and line a 9-inch square or round cake pan.
02 - In a large bowl, whisk together mashed bananas, eggs, vegetable oil, granulated sugar, light brown sugar, and vanilla extract until fully blended and smooth.
03 - In a separate bowl, whisk together all-purpose flour, baking soda, baking powder, ground cinnamon, and salt until evenly distributed.
04 - Gradually add the dry mixture to the wet ingredients, stirring gently until combined. Take care not to overmix.
05 - If desired, fold in chopped walnuts, pecans, or chocolate chips until distributed throughout the batter.
06 - Pour the batter into the prepared pan, smoothing the surface. Place in the oven and bake for 35 to 40 minutes, or until a toothpick inserted in the center emerges clean.
07 - Allow the baked cake to cool in the pan for 10 minutes. Transfer to a wire rack and let it cool completely before slicing. Serve warm or at room temperature.