Preheat Oven:
Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or foil for easy cleanup.

Prep the Brussels Sprouts:
Wash and trim the ends off the Brussels sprouts. Cut them in half lengthwise and pat them dry with a paper towel to remove excess moisture.

Season and Toss:
In a large mixing bowl, toss the halved Brussels sprouts with olive oil, garlic powder, onion powder, salt, and pepper until evenly coated.

Add Parmesan:
Sprinkle grated Parmesan over the Brussels sprouts and toss again gently, allowing the cheese to stick to the oiled surfaces.

Arrange and Roast:
Spread the Brussels sprouts in a single layer, cut side down, on the prepared baking sheet. Roast for 25–30 minutes, or until the cut sides are deeply golden and crispy.

Serve Hot:
Serve immediately while crisp and hot. Garnish with extra Parmesan if desired.