Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan generously with butter or non-stick spray, then line it with a strip of parchment paper so two sides hang over the edges — this makes removing the loaf effortless.

Wash and trim the zucchini. Using the large holes of a box grater, shred the zucchini directly into a measuring cup until you have 1½ cups loosely packed. Do not squeeze out the moisture — it's essential to the texture of the bread.

In a large mixing bowl, whisk together the eggs, vegetable oil, granulated sugar, brown sugar, and vanilla extract until smooth and well combined, about 1 minute.

Add the shredded zucchini to the wet ingredients and stir to combine.

Add the flour, baking soda, baking powder, salt, cinnamon, and nutmeg directly to the bowl. Using a rubber spatula or wooden spoon, fold everything together until just combined — do not overmix. A few small flour streaks are fine. Fold in chocolate chips or walnuts at this stage if using.

Pour the batter into the prepared loaf pan and spread it into an even layer. For an extra-beautiful crust, sprinkle the top with 1 tablespoon of granulated sugar mixed with a pinch of cinnamon.

Bake on the center rack for 55 to 65 minutes, until the top is deep golden brown and a toothpick inserted into the very center comes out with just a few moist crumbs (not wet batter). If the top is browning too quickly after 40 minutes, tent loosely with aluminum foil for the remainder of the bake.

Remove from the oven and let the bread cool in the pan for 15 minutes. Then, using the parchment overhang, lift the loaf out onto a wire rack and cool for at least 20 more minutes before slicing. (This step is non-negotiable for a clean, moist slice.)