Preheat oven to 180ºC (356ºF). Grease with butter a round 8-inch baking pan and line with baking paper, set aside. NOTE: Alternatively, if you have a quality non-stick pan, liberally grease it with melted butter and dust it with a light layer of flour. This will leave your finished cake with smooth sides.
In a large mixing bowl, add flour, baking powder, and baking soda. Whisk together until well combined.
Add sugar and whisk until well combined.
Peel bananas and mash in a bowl with a fork or potato masher.
Add in mashed banana, milk, oil, vinegar, and vanilla. Gently fold with a spatula until well combined, ensuring not to over-mix, just ensure there are no large pockets of flour remaining in the batter.
Pour batter into the prepared baking pan. Smoothing out the top.
Transfer to oven and bake for 40-45 minutes, until a toothpick inserted into the middle comes out clean and it’s lightly golden on top and looks set.
Remove from the oven and allow the cake to cool in the pan for 15 minutes.
Transfer to a wire rack to cool completely.
Once cooled, pour maple syrup into a small bowl and take a pastry brush and brush a layer or desired amount of syrup over the cake.
Serve and enjoy!