Preheat oven to 430 degrees F (220 degrees C). Line a baking sheet with parchment paper.
Pour milk into a bowl. Combine bread crumbs, Parmesan cheese, garlic powder, and black pepper in a shallow bowl. Place zucchini slices in the milk; soak for 1 minute. Remove zucchini slices from milk and press each into the bread crumbs mixture until coated on both sides. Arrange coated zucchini slices on the prepared baking sheet.
Bake in the preheated oven until chips are crisp, about 30 minutes.