01 - Preheat oven to 350°F. Grease and line a 9-inch square or round cake pan.
02 - In a large mixing bowl, whisk 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.
04 - Gradually add dry mixture to the wet ingredients, stirring gently until just combined. Avoid overmixing to maintain a tender crumb.
05 - Carefully fold in chopped walnuts or pecans and chocolate chips, if using.
06 - Transfer batter to the prepared pan, smoothing the surface evenly. Bake in the center of the oven for 35 to 40 minutes, or until a toothpick inserted into the center emerges clean.
07 - Allow cake to cool in the pan for 10 minutes. Turn out onto a wire rack and cool completely before serving warm or at room temperature.