1. Prepare your oven and pan:
Preheat your oven to 350°F (175°C). Grease a 9×5-inch loaf pan or line it with parchment paper for easy removal.

2. Mix the dry ingredients:
In a large bowl, whisk together flour, baking soda, baking powder, salt, cinnamon, and nutmeg.

3. Combine the wet ingredients:
In a separate bowl, whisk together oil, sugars, eggs, and vanilla until smooth and glossy.

4. Add zucchini:
Fold the grated zucchini into the wet mixture until well combined.

5. Mix batter:
Gradually add the dry ingredients into the wet, mixing gently until just combined. Do not overmix—this keeps your bread soft and fluffy.

6. Make the cinnamon swirl:
Pour half the batter into the prepared pan. In a small bowl, mix the topping ingredients. Sprinkle half over the batter layer. Add the remaining batter on top and finish with the rest of the cinnamon sugar.

7. Bake:
Bake for 50–60 minutes or until a toothpick inserted in the center comes out clean. Tent with foil halfway through if the top browns too quickly.

8. Cool:
Allow the bread to cool in the pan for 10–15 minutes, then transfer to a wire rack to cool completely before slicing.