Preheat your oven to 400°F (200°C). Preheating ensures that the oven is hot enough to roast the Brussels sprouts quickly and evenly.
Wash the Brussels sprouts under cold water and pat them dry with a clean kitchen towel or paper towels. Trim off the stem end of each Brussels sprout and remove any loose or discolored outer leaves.
For faster and more even cooking, slice the Brussels sprouts in half lengthwise. If the Brussels sprouts are large, you can quarter them for bite-sized pieces.
Place the sliced Brussels sprouts in a large mixing bowl. Drizzle with olive oil, enough to coat the Brussels sprouts evenly. Season with salt and pepper to taste, and any additional seasonings you like, such as garlic powder, onion powder, or smoked paprika.
Toss the Brussels sprouts in the bowl until they are evenly coated with the olive oil and seasonings. Use your hands or a spoon to ensure every piece is well coated.
Spread the seasoned Brussels sprouts in a single layer on a baking sheet lined with parchment paper or aluminum foil. Make sure the Brussels sprouts are not overcrowded on the baking sheet, as this allows them to roast evenly.
Place the baking sheet in the preheated oven and roast the Brussels sprouts for 20-25 minutes, or until they are golden brown and tender, with crispy edges. You can flip the Brussels sprouts halfway through the cooking time for even browning.
Once the Brussels sprouts are roasted to your desired level of crispiness, remove them from the oven and transfer them to a serving dish. Serve hot as a side dish alongside your favorite main course.