01 - Preheat oven to 350°F (175°C). 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 the 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 ingredients to the wet ingredients while stirring gently. Mix until just combined without overmixing.
05 - Fold in chopped nuts or chocolate chips if desired.
06 - Pour batter into the prepared cake pan and smooth the surface.
07 - Bake for 35–40 minutes, or until a toothpick inserted into the center comes out clean.
08 - Allow cake to cool in the pan for 10 minutes. Transfer to a wire rack and cool completely before slicing. Serve warm or at room temperature.