Preheat oven to 425 degrees. Line a large baking sheet with foil and spray with an olive oil mister, or non-fat cooking spray.
In a small bowl, combine the parmesan, Panko, garlic powder and salt and pepper.
Place green beans on baking sheet, making sure they are spread out evenly and not overlapping. Mist them lightly with an olive oil mister or non-fat cooking spray.
Sprinkle Parmesan cheese mixture evenly over all the green beans. Place in oven and bake for about 12-15 minutes, or until green beans are golden brown and begin to crisp.