Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper or a silicone baking mat. This ensures the chips don’t stick and helps with even browning.
Wash the zucchinis and pat them dry. Slice them into 1/4-inch thick rounds. It is important to keep the slices uniform in thickness so they all cook at the same rate. If they are too thin, they might burn; if they are too thick, they won’t get crispy.
In a small shallow bowl, whisk the egg until smooth. In a second shallow bowl, combine the Parmesan cheese, panko breadcrumbs, garlic powder, dried oregano, salt, and black pepper. Stir the dry mixture well to distribute the spices evenly.
Dip each zucchini slice into the whisked egg, letting any excess drip off. Then, press the slice into the Parmesan and breadcrumb mixture, ensuring both sides are well-coated. Place the coated slices in a single layer on the prepared baking sheet.
Place the baking sheet in the oven and bake for 15 to 20 minutes. Halfway through the cooking time, carefully flip the chips to ensure both sides get crispy. Remove from the oven when the coating is a deep golden brown.