01 - Preheat the oven to 350°F. Grease and flour a 9-inch round cake pan or line it with parchment paper.
02 - In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
03 - In a large bowl, beat the mashed bananas with sugar, vegetable oil, eggs, milk, and vanilla extract until smooth and well incorporated.
04 - Gradually fold the dry ingredient mixture into the banana mixture, stirring gently until just combined. Avoid overmixing to keep the crumb tender.
05 - If using, gently fold the chopped nuts or chocolate chips into the batter.
06 - Pour the batter into the prepared cake pan and smooth the top with a spatula for an even surface.
07 - Bake for 40 to 45 minutes, or until a toothpick inserted into the center of the cake comes out clean.
08 - Let the cake cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before serving.
09 - Slice into wedges and serve plain or topped with your favorite frosting.