Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper or a silicone baking mat to prevent sticking and ensure the bites crisp up evenly.
Wash the zucchinis and pat them completely dry with a towel. Slice them into rounds about 1/4 inch thick. Keeping the slices uniform ensures they all cook at the same rate.
In a shallow bowl, combine the grated Parmesan cheese, Panko breadcrumbs, dried oregano, garlic powder, salt, and pepper. Stir the mixture well so the seasonings are evenly distributed.
Place the zucchini slices in a large bowl and toss them with the olive oil until lightly coated. One by one, press the slices into the Parmesan mixture, coating both sides firmly. Place them in a single layer on the prepared baking sheet.
Place the baking sheet in the center of the oven and bake for 15 to 20 minutes. The coating should be golden brown and the zucchini should be tender. For extra crispiness, you can broil them for the last 60 seconds, watching closely to prevent burning.