Preheat your oven to 350°F (175°C) and grease a 9x5 inch loaf pan.
In a bowl, whisk together the flour, baking soda, baking powder, salt, and cinnamon.
In another bowl, mix the granulated sugar, brown sugar, eggs, and oil until well combined.
Add the grated zucchini and vanilla extract to the wet ingredients and stir.
Gradually add the dry ingredients to the wet mixture, stirring until just combined.
If desired, fold in the chopped walnuts for added texture.
Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted comes out clean.
Allow the bread to cool in the pan for 10 minutes before transferring to a wire rack.
Slice and serve warm or at room temperature.