Preheat the oven to 180°C (350°F) Gas mark 4, and butter an 8 x 4-inch loaf tin.
In a bowl, mash the ripe bananas and then stir in the melted butter.
Then stir in the baking soda, salt, sugar, egg, and vanilla extract.
Then gently stir in the plain flour and mix in until well combined.
Pour the batter into loaf tin.
Bake for 60 minutes. (See Note 1).
Remove from the oven and let it cool down in the loaf tin for a few minutes.
Then remove the banana bread from the tin and let it cool down.
Once the bread is cooled down, cut it into slices using a bread knife and serve.