Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.
In a mixing bowl, combine the all-purpose flour, whole wheat flour, baking powder, baking soda, cinnamon, nutmeg, ginger, and salt. Whisk until well mixed and set aside.
In another large bowl, whisk together the granulated sugar, brown sugar, pumpkin puree, grated zucchini, vegetable oil, eggs, and vanilla extract until smooth.
Gradually add the dry ingredients to the wet ingredients. Stir gently using a rubber spatula until just combined. Be careful not to overmix.
If desired, fold in the chopped walnuts or pecans.
Pour the batter into the prepared loaf pan, smoothing the top with the spatula.
Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
Once baked, allow the bread to cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely.