Preheat your oven to 350°F (175°C). This ensures that the bread bakes evenly and rises properly.

Grease a 9x5 inch loaf pan with cooking spray or butter, and optionally line it with parchment paper for easy removal.

In a large mixing bowl, whisk together the flour, baking soda, baking powder, cinnamon, nutmeg, and salt. This helps to evenly distribute the leavening agents and spices throughout the flour.

In another bowl, combine the grated zucchini, granulated sugar, brown sugar, vegetable oil, eggs, and vanilla extract. Mix until well combined. The oil keeps the bread moist, while the sugars add sweetness.

Gradually add the wet mixture to the dry ingredients, using a rubber spatula to fold them together. Be careful not to overmix; a few lumps are okay. Overmixing can lead to a dense bread.

If using, gently fold in the chopped walnuts. They add a nice crunch and flavor to the bread.

Pour the batter into the prepared loaf pan and smooth the top with the spatula. Bake in the preheated oven for 55-60 minutes, or until a toothpick inserted into the center comes out clean. This ensures that the bread is fully cooked.

Once baked, remove the bread from the oven and let it cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.

Slice the zucchini bread once it has cooled. It can be enjoyed plain or with a spread of butter or cream cheese.