Preheat the oven to 400ºF. Coat a large baking sheet with olive oil spray and set aside.
In a large plastic resealable storage bag, combine potatoes, flour, Parmesan, and panko. Seal the bag before carefully shaking and massaging it until the potatoes are completely coated. Transfer coated potatoes to the prepared baking sheet and arrange in a single layer. Sprinkle with salt and pepper, then spray the top lightly with olive oil spray.
Bake until golden brown and crispy, about 45 minutes, flipping the potatoes once halfway through. Sprinkle with a little chopped parsley and serve.