Preheat oven to 170 degrees celcius. Grease and flour a 9X5- inch loaf tin.
Mash the bananas with a fork. In a large mixing bowl, whisk together sugar and eggs until well incorporated. Whisk in the mashed bananas and buttermilk.
Sift into egg mixture the flour, baking powder, bicarbonate of soda, cinnamon, ginger, nutmeg and salt, then mix until combined.
Stir in the melted butter and vanilla extract and mix until combined.
Pour into the prepared loaf tin and bake for 1 hour or until a toothpick or skewer inserted in the centre comes out clean. 30 minutes into baking, loosely cover the bread with foil t o help prevent the top and sides from getting too brown. Leave tin to cool for 15 minutes, then run a knife around the edge and invert onto cooling rack.