01 - Preheat the oven to 350°F. Grease and line a 9-inch square or round cake pan.
02 - In a large mixing bowl, whisk together the mashed bananas, eggs, vegetable oil, granulated sugar, light brown sugar, and vanilla extract until the mixture is smooth.
03 - In a separate bowl, combine the all-purpose flour, baking soda, baking powder, ground cinnamon, and salt. Whisk until evenly distributed.
04 - Gradually add the dry mixture to the wet mixture, stirring until just combined. Avoid overmixing.
05 - Fold in chopped walnuts, pecans, or chocolate chips if using.
06 - Pour the batter into the prepared pan and smooth the surface evenly with a spatula.
07 - Bake for 35 to 40 minutes, or until a toothpick inserted in the center emerges clean.
08 - Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Serve warm or at room temperature.