Add in a little flour and one egg. Mix through, repeat with the other egg and the rest of flour, baking powder, vanilla and a pinch of salt until everything is mixed through and smooth.
Pour the mix into the prepared loaf tin, slice the remaining banana in half lengthways and arrange on the top of the loaf. Sprinkle with the remaining brown sugar then place in the oven for approximately 50-55 minutes. It should be risen, golden and a skewer comes out clean when the banana bread is ready. Cool for 10 minutes in the tin before turning out onto a wire rack to cool completely.