Preheat oven to 450°F and line a baking sheet with parchment paper (optional for easy cleanup)
Place zucchini slices on the baking sheet and drizzle with olive oil. Toss until well-coated. Spread slices out into a single layer.
Sprinkle generously with garlic salt, salt, and pepper.
Top each slice with parmesan.
Bake on center rack for about 10 minutes, until zucchini is just fork tender. Set broiler on high and broil for 2 to 3 minutes, until cheese is bubbly and browned.