Preheat your oven to 425°F. Line a baking sheet with parchment paper for easy cleanup.
In a large bowl, combine the halved Brussels sprouts, olive oil, garlic powder, onion powder, salt, and black pepper. Toss until the Brussels sprouts are evenly coated.
Spread the Brussels sprouts in a single layer on the prepared baking sheet. Sprinkle the grated Parmesan cheese evenly over the top.
Roast in the preheated oven for 20-25 minutes, or until the Brussels sprouts are golden brown and crispy, stirring halfway through for even cooking.
If desired, sprinkle with red pepper flakes before serving for an added kick.
Serve immediately while hot and crispy.