Preheat your oven: Set it to 425°F (220°C).
Line a large baking sheet with parchment paper for easy cleanup.
Prep the zucchini: Slice the zucchini into 1/2-inch rounds or cut into spears. Keep pieces even so they cook at the same rate.
Dry it well: Pat the slices with paper towels to remove excess moisture. This step helps the coating stick and crisp up.
Season the oil: In a bowl, mix the oil with garlic powder, onion powder, paprika, salt, and pepper.
Toss zucchini to coat evenly.
Add Parmesan: Sprinkle the Parmesan over the zucchini and toss again. The cheese should stick to the oiled surfaces.
Arrange on the sheet: Spread the pieces in a single layer with space between them. Crowding leads to steaming, not crisping.
Bake: Cook for 12–15 minutes, flipping halfway through so both sides get color.
Bake until edges are golden and the zucchini is tender but not mushy.
Finish and serve: Taste and adjust salt if needed. Garnish with fresh herbs and a pinch of red pepper flakes if you like. Serve hot.