Preheat oven to 450 degrees and line a baking sheet with aluminum foil.
Place the Brussels sprouts on the baking sheet and drizzle with olive oil, tossing to coat. Sprinkle with garlic powder and salt and pepper. Try to make sure all of the Brussels are faced down on the pan to get a good sear. Place the pieces of bacon evenly on the pan.
Bake for 15-25 minutes, tossing halfway. Start checking them at 15 minutes. The bake time of the sprouts will depend on the size of them and your oven. Bake until the Brussels sprouts are fork tender but not mushy. Remove from the oven and toss with the balsamic vinegar and serve immediately.