In a small bowl, combine panko and the remaining tablespoon of oil. Set aside.
In a large mixing bowl toss to combine florets, salt, pepper, 3 tablespoons oil, and lemon juice. Evenly layer on a parchment-lined cooking sheet. Cook for 20 minutes. Sprinkle on prepared panko and cook an additional 15 minutes. Lastly, sprinkle with parsley and parmesan. Bake an additional 2-3 minutes.