Preheat the oven to 350 degrees F (180 degrees C). Grease your loaf and sprinkle about a tablespoon of flour evenly on it.
Mix All-Purpose Flour (2 cup), Baking Powder (2 teaspoon), Baking Soda (1 teaspoon) and Salt (1 pinch) in one bowl.
Mix Egg (2), Butter (1/2 cup), Vanilla Extract (1 teaspoon), Milk (3 tablespoon), Lemon Juice (1 tablespoon), Banana (1 cup), and Caster Sugar (1 cup) in another.
Slowly pour the dry ingredients into the wet mixture. Combine but don’t over-stir. Pour the batter into the prepared loaf pan and bake for one hour.