Preheat the oven to 425 degrees F (220 degrees C). Move the rack to the upper third of the oven. Drizzle a small amount of oil in the bottom of a 9x13-inch baking dish.
Combine Brussels sprouts, water, garlic, salt, and pepper in a bowl and toss to coat. Spread mixture into the prepared baking dish in a single layer.
Bake in the preheated oven for about 25 minutes. Toss and continue baking until caramelized to taste, about 10 minutes more. Remove from oven, add butter, and cover with Parmesan cheese. Continue baking about 10 minutes more. Toss Brussels sprouts in the pan, scraping up brown bits, before serving.
