Preheat your oven to 350°F (175°C). Grease and flour your loaf pan.
In a large mixing bowl, whisk together the mashed bananas, pumpkin puree, softened butter, granulated sugar, brown sugar, eggs, and vanilla extract until smooth and well combined.
In a separate bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, nutmeg, and ginger.
Gradually add the dry ingredients to the wet ingredients, stirring just until combined. Be careful not to overmix. If desired, fold in the chopped nuts.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake in the preheated oven for about 60 minutes, or until a toothpick inserted into the center comes out clean.
Allow the bread to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely before slicing.