Preheat oven to 425°F. Line a baking sheet with parchment paper.
Slice the prepared Brussels sprouts in half. Save any leaves that fall off. Place the halved sprouts and leaves on the lined baking sheet.
Cut the bacon into small strips or chunks and add them to the baking sheet with the sprouts.
In a small bowl, whisk together the oil, vinegar, salt, and pepper. Drizzle the mixture over the sprouts and bacon. Toss everything a few times to make sure all pieces are evenly coated, then spread out the sprouts and bacon in a single, evenly spaced layer on the baking sheet.
Bake for 15 minutes, then stir or flip the sprouts to ensure even baking. Continue baking until the sprouts and bacon are golden brown, crispy, and slightly charred, about another 10-15 minutes. For extra crispness, broil for 1-2 minutes, watching closely to prevent burning.
Remove the baking sheet from the oven and let the sprouts rest on the pan for 1-2 minutes. Serve immediately.