01 - Set the oven to 425°F. Line a baking sheet with parchment paper.
02 - Toss Brussels sprouts with olive oil, sea salt, black pepper, and optional garlic powder and chili flakes in a large bowl.
03 - Spread the Brussels sprouts cut side down in a single layer on the prepared baking sheet for optimal caramelization.
04 - Roast for 20–25 minutes, stirring once halfway through, until the sprouts are golden brown and crispy at the edges.
05 - Remove from oven and, if using, sprinkle lemon zest before serving.