Heat the oven to 350°F. Coat a loaf pan with nonstick cooking spray, then line it with parchment paper so the bread lifts out easily after baking.

Place the ripe bananas in a large mixing bowl and mash until mostly smooth. Whisk in the vegetable oil, granulated sugar, brown sugar, eggs, and pumpkin puree until the mixture is fully combined.

In another bowl, whisk together the flour, pumpkin pie spice, baking soda, baking powder, and salt until evenly mixed.

Add half of the dry ingredients to the wet ingredients and gently fold together. Add the remaining dry mixture and continue folding just until no streaks of flour remain. Be careful not to overmix, which can make the bread dense.

If you're using walnuts, gently fold them into the batter until evenly distributed.

Transfer the batter to the prepared loaf pan and spread the top into an even layer. Bake for 50 to 55 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs.

Let the loaf cool in the pan for about 10 to 15 minutes, then transfer it to a wire rack to cool completely or slice while it's still slightly warm. Enjoy as is or with a little butter for an extra cozy treat.