Usually I heat oven to 450F and bake it for 10 mins then kick it down to 400ishF for about an hour.
If that doesn't work, try this: make Naan, let it cool. Then make some vinagrette to marinate the zucchini in for about45 mins then toss it on the BBQ once it reaches about 250F or 300F for 3 minutes then flip and 2 or so on the other. Then I grill the Naan just so it gets heated up and has some grill marks. Not real zucchini bread I know but it's a substitute.