01 - Preheat oven to 350°F. Grease and line a 9-inch square or round cake pan with parchment.
02 - In a large mixing bowl, whisk together mashed bananas, eggs, vegetable oil, granulated sugar, light brown sugar, and vanilla extract until completely smooth.
03 - In a separate bowl, combine all-purpose flour, baking soda, baking powder, ground cinnamon, and salt. Whisk to blend.
04 - Gradually add dry ingredients to the wet mixture, gently stirring until fully combined. Avoid overmixing to maintain a tender crumb.
05 - Gently fold in chopped walnuts, pecans, or chocolate chips, if using.
06 - Transfer the batter to the prepared cake pan. Spread evenly using a spatula to ensure even baking.
07 - Bake for 35 to 40 minutes, or until a toothpick inserted in the center emerges clean with minimal crumbs.
08 - Allow the cake to cool in the pan for 10 minutes before transferring to a wire rack. Cool completely before slicing. Serve warm or at room temperature.