Preheat the air fryer to 400°F (200°C) for about 5 minutes.
In a large bowl, combine the sliced zucchini and squash.
Drizzle the olive oil over the vegetables and toss to coat evenly.
Sprinkle the garlic powder, onion powder, Italian seasoning, salt, and black pepper over the veggies. Toss again to ensure all pieces are well-seasoned.
If using, sprinkle the grated Parmesan cheese over the mixture and toss gently.
Place the seasoned zucchini and squash in the air fryer basket in a single layer. You may need to do this in batches depending on the size of your air fryer.
Cook for 10-12 minutes, shaking the basket halfway through, until the vegetables are golden brown and crispy.
Remove from the air fryer and serve immediately.