01 - Preheat the 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, brown sugar, and vanilla extract until smooth.
03 - In a separate bowl, whisk together flour, baking soda, baking powder, ground cinnamon, and salt.
04 - Gradually stir the flour mixture into the banana mixture until just combined. Avoid overmixing.
05 - Gently fold in chopped nuts or chocolate chips if desired.
06 - Pour the batter into the prepared pan and smooth the top. Bake for 35 to 40 minutes, or until a toothpick inserted in the center comes out clean.
07 - Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Serve warm or at room temperature.