Preheat the oven to 400°F (200°C). Line a large baking sheet with parchment paper or foil.
Place the trimmed asparagus spears on the baking sheet in a single layer.
Drizzle the asparagus with olive oil and sprinkle with salt, pepper, and garlic. Toss gently to coat evenly.
Scatter the chopped bacon evenly over the asparagus, making sure the pieces are not overlapping too much.
Roast in the preheated oven for 12–15 minutes, until the asparagus is tender and the bacon is mostly cooked.
Remove the pan from the oven and sprinkle the parmesan cheese evenly over the asparagus and bacon.
Return to the oven and roast for another 3–5 minutes, until the cheese is melted and lightly golden.
For extra browning, broil for 1–2 minutes, watching closely to prevent burning.
Serve immediately while hot and crispy.