Preheat the oven to 400°F (200°C). Arrange the zucchini, cut sides up, in an ovenproof dish large enough to hold them in a single layer. Lightly brush with the olive oil and season with the salt and pepper. In a small bowl mix the Parmesan cheese and garlic together, then sprinkle over the zucchini.
Bake for about 15 minutes, or until the zucchini are tender and the cheese is browned.