Set the oven to preheat at 400°F (204°C), and optionally, line a baking sheet with foil.
Place the trimmed asparagus spears on the prepared baking sheet in a single, even layer, aligning them in the same direction.
Drizzle the olive oil evenly over the asparagus. Season with sea salt, black pepper, and garlic powder if using.
Using your hands or kitchen tongs, gently toss and turn the asparagus to ensure each spear is uniformly coated with the oil and seasoning. Re-spread into a single layer.
Roast in the oven until spears reach a crisp-tender texture: allow 8–11 minutes for thinner stalks, 12–15 minutes for medium ones, and 16–20 minutes for thicker asparagus. Cooking time will vary depending on thickness.