1. 1. Preheat your oven to 225°F (107°C). Line two large baking sheets with parchment paper for easy cleanup.

2. 2. Wash and thinly slice the zucchini. Aim for slices about 1/16 to 1/8 inch thick. Use a mandoline for the most consistent, crispy zucchini chips.

3. 3. Lay the zucchini slices on paper towels. Blot them thoroughly with more paper towels to remove as much moisture as possible. This is crucial for truly crispy zucchini chips.

4. 4. In a large bowl, toss the dried zucchini slices with olive oil, garlic powder, onion powder, salt, and pepper. If using, add the Parmesan cheese now. Ensure every slice is lightly coated.

5. 5. Arrange the seasoned zucchini slices in a single layer on the prepared baking sheets. Do not overcrowd the pan; give them space to crisp up. You might need to use more than two sheets.

6. 6. Bake for 45 minutes, then carefully flip each zucchini chip. Continue baking for another 30-45 minutes, or until the crispy zucchini chips are golden brown and perfectly crisp.

7. 7. Remove from the oven and let them cool on the baking sheets. They will become even crispier as they cool. Enjoy your homemade crispy zucchini chips!