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 mixture is smooth.
03 - In a separate bowl, whisk together all-purpose flour, baking soda, baking powder, ground cinnamon, and salt.
04 - Gradually add the dry ingredient mixture to the wet base, stirring just until combined. Do not overmix.
05 - Gently fold in chopped nuts or chocolate chips if desired.
06 - Pour batter into prepared pan and smooth the surface evenly.
07 - Bake for 35 to 40 minutes or until a toothpick inserted in the center comes out clean.
08 - Allow to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Slice and serve warm or at room temperature.