Preheat your oven to 350°F (175°C). Grease and flour a 9x5-inch loaf pan.
In a large bowl, whisk together the mashed bananas, pumpkin puree, eggs, vegetable oil, granulated sugar, and vanilla extract until well combined.
In a separate bowl, sift together the all-purpose flour, baking soda, baking powder, salt, ground cinnamon, ground nutmeg, and ground cloves.
Gradually add the dry ingredients to the wet ingredients, stirring gently until just combined. Avoid overmixing.
If using, fold in the chopped nuts.
Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
Bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean.
Allow the loaf to cool in the pan for 10 minutes before transferring it to a wire rack to cool completely.