01 - Preheat oven to 350°F. Grease and line a 9-inch square or round cake pan with parchment paper.
02 - In a large mixing bowl, whisk together mashed bananas, eggs, vegetable oil, granulated sugar, light brown sugar, and vanilla until the mixture is smooth.
03 - In a separate mixing bowl, whisk together all-purpose flour, baking soda, baking powder, ground cinnamon, and salt until well blended.
04 - Gradually add dry ingredients to the wet mixture, stirring gently until just combined. Avoid overmixing for best texture.
05 - Gently fold in chopped nuts or chocolate chips, if desired.
06 - Pour batter into the prepared cake pan and smooth the surface. Bake for 35–40 minutes or until a toothpick inserted into the center comes out clean.
07 - Let the cake rest in the pan for 10 minutes, then transfer to a wire rack to cool completely. Serve warm or at room temperature.