Preheat the oven 350°F/175°C. Grease and flour the 9x5 inch loaf pan, or you can grease and line the bottom and the sides with parchment paper.
In a medium bowl, whisk together the flour, baking powder, baking soda, salt and spices. Set aside.
In a large bowl, mash the bananas until smooth and no more large chunks. Add the sugar and oil and whisk together until they’re well combined. Add in eggs, one at a time and whisk until it’s well combined. Add in the pumpkin puree and whisk until it's completely smooth.
Carefully add the wet mixture into the flour mixture and fold, using a rubber spatula.
Pour the batter into the prepared pan and bake for 55-60 minutes, or until an inserted toothpick comes out clean or with a few moist crumbs. The loaf should not be wobbly if you shake the pan. If it does wobble, allow it to bake for another 5-10 minutes.
Remove from the oven and let the bread cool for 15 minutes on a wire rack, then turn it out from the pan and allow it to cool completely.
The bread is best served at room temperature. Keep the bread in the fridge for up to 5 days and frozen for up to 2 months (thaw overnight in the fridge).