Preheat your oven to 350°F (175°C). Wash and scrub zucchinis thoroughly, grate them, and ensure to pack firmly into measuring cup to get 2 cups.

In a large bowl, combine the grated zucchini, oil, brown sugar, granulated sugar, eggs, and vanilla extract. Mix well until smooth.

Fold in flour, baking soda, baking powder, salt, cinnamon, and nutmeg. Stir gently until just combined, being careful not to overmix.

Spray a 1.5 lb loaf pan with non-stick spray. Pour in the batter, smoothing the top. Fill about halfway.

Bake for 40 to 45 minutes until golden-brown. If the top browns too quickly, tent it with aluminum foil.

Check for doneness by inserting a toothpick; it should come out clean. If needed, return to oven in 5-minute increments.

Once baked, cool in the pan for 10 minutes, then transfer to a wire rack to cool completely for easier slicing.