Preheat the oven to 450°F with a rack in the center position.
In a large bowl, toss the zucchini with the olive oil, salt, pepper and garlic powder.
Arrange on a rimmed sheet pan in a single layer, top with the Parmesan cheese and bake for 5 minutes. Turn the oven broiler to High. Continue to bake until the cheese is golden brown and the zucchini is tender, about 2-3 minutes.