First, prep your Brussels sprouts. For medium-sized or traditional-sized sprouts, simply trim the stubby ends and then cut them in half. However for larger sprouts, trim the ends and then quarter them. Here's a tip: for a shortcut, buy pre-cut Brussels such as what I have here:
Preheat your oven to 400°F (approx. 204°C).
Place the Brussels sprouts in a mixing bowl and toss with the oil. Add the garlic powder, if using, along with the salt and pepper, and toss again. Tip: No need to wash your bowl right away—you’ll be using it again after the Brussels sprouts have roasted!
Spread the sprouts evenly on a parchment-lined or nonstick baking sheet (or two), cut side down.
Roast for 15 minutes. Remove the sprouts from the oven to flip, then reduce your oven temperature to 350°F (approx. 177°C). Immediately return the Brussels sprouts to the oven for an additional 15–20 minutes or until brown and crispy.
Meanwhile, cook the bacon in a skillet until browned on both sides, if using. If your bacon seems overly dry, coat each side lightly with oil. Once cool enough to handle, chop or slice it into small pieces.
Transfer your roasted sprouts back to the mixing bowl and toss with the chopped bacon and balsamic glaze to evenly coat. Taste and add more salt and pepper as needed. Spoon the Brussels sprouts onto your serving dish of choice and serve immediately.