Preheat your oven to 350°F (175°C) and grease a loaf pan with butter or non-stick cooking spray.
In a mixing bowl, combine 2 cups of all-purpose flour, 1 teaspoon of baking soda, 1/2 teaspoon of baking powder, 1/2 teaspoon of salt, and 1 teaspoon of pumpkin pie spice. Stir until well mixed.
In a separate bowl, mash 2 ripe bananas until smooth. Add 1 cup of pumpkin puree, 1/2 cup of granulated sugar, 1/2 cup of brown sugar, 1/3 cup of vegetable oil, 2 large eggs, and 1 teaspoon of vanilla extract. Mix until well combined.
Pour the wet ingredients into the bowl with the dry ingredients. Stir until just combined. Be careful not to overmix, as this can result in a dense bread.
If desired, fold in additional mix-ins such as chopped nuts (like walnuts or pecans) or chocolate chips for extra flavor and texture.
Pour the batter into the prepared loaf pan, spreading it evenly.
Place the loaf pan in the preheated oven and bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean. The baking time may vary depending on your oven, so keep an eye on it towards the end.
Once baked, remove the bread from the oven and allow it to cool in the pan for about 10 minutes. Then, transfer it to a wire rack to cool completely before slicing and serving.