In a large bowl, mix together the dry ingredients - flour, baking powder and baking soda.
In another bowl, mix together the melted butter and sugar.
Add the eggs to the butter sugar mixture and beat the mixture well using a balloon whisk for best results.
Add the vanilla extract to the egg butter sugar mixture and mix using a spoon.
Add the mashed bananas and the egg butter sugar mixture to the dry flour mixture.
Mix all ingredients together, you may use a balloon whisk or mixer to blend the ingredients and to avoid any lumps. It is important not to over mix the ingredients, just mixing for few seconds is enough.
Grease a cake pan with butter and pour the cake batter in to it.
Bake for about 40 minutes or until a toothpick inserted in the center of the cake comes out clean. In case the top of the cake browns before the inside is completely cooked, cover the top with aluminium foil and bake for the rest of the time.
Allow the cake to cool in the rack.
After cooling the cake completely, you can apply the vanilla whipped cream frosting or use cream cheese frosting like vanilla cream cheese frosting (which will last more if you want to keep at room temperature for longer time) etc or enjoy the cake as it is!For more servings of cakes with creamy fillings in between the layers, you can double the recipe to make two banana cakes at the same time and use the whipped cream frosting or cream cheese frosting to fill between the layers and also do the topping.Keep in mind that whipped cream frosting is more lighter in texture and will melt faster in room temperature. So make sure to store the cake in refrigerator once you have frosted the cake and until ready to serve. If you wish to store the cake in room temperature for more time, it is a good idea to use cream cheese frosting which will last more better at room temperature (though it is ideal to refrigerate once frosted).