Preheat your oven to 425°F (220°C).
Wash and dry the broccoli florets thoroughly.
In a large bowl, combine the broccoli with olive oil.
Sprinkle garlic powder, salt, and black pepper over the broccoli.
Toss the mixture until the florets are evenly coated.
Spread the broccoli on a baking sheet in a single layer.
Roast in the preheated oven for 15-20 minutes until edges are crispy.
Halfway through, stir the broccoli for even roasting.
If using, sprinkle Parmesan cheese during the last 5 minutes of roasting.
Remove from oven and let cool slightly before serving.