Heat oven to 350°F. Grease a 9x5-inch loaf pan and line with a parchment sling.
Squeeze excess moisture from the shredded zucchini with a clean towel. Set aside.
Whisk flour, baking soda, baking powder, salt, cinnamon, and nutmeg in a large bowl.
Whisk oil, beaten eggs, vanilla, granulated sugar, and brown sugar until smooth and glossy.
Pour the wet mixture into the dry ingredients. Stir gently until just combined.
Fold in the zucchini, then walnuts and chocolate chips if using. Do not overmix.
Scrape batter into the pan and smooth the top. Tap once to release bubbles.
Bake 50–60 minutes, until a tester comes out with just a few moist crumbs.
Cool in the pan 10 minutes. Lift out, then cool completely on a rack before slicing.
Notes
Variation: Swap half the oil for unsweetened applesauce for a lighter loaf. Add a tablespoon of turbinado sugar on top for extra crunch. Storage: Wrap tightly and keep at room temperature for 2 days, or refrigerate up to 5 days. Freezes well for 2 months.This recipe is an original creation inspired by classic Grandma's Zucchini Bread flavors. All ingredient ratios and instructions are independently developed.