Wash, pat dry, and remove the outer leaves from the Brussels sprouts. Cut them in half and turn on the oven to 400 F.
Put the cut Brussels sprouts in a large bowl and drizzle the olive oil over them. Mix in the minced garlic, red pepper flakes, salt, and pepper. Toss well.
Place them on a baking sheet, cut side down, and bake for 10 mins.
Take the baking sheet out of the oven and sprinkle the grated Parmesan cheese evenly on top of the Brussels sprouts.
Continue baking for an additional 10-15 mins until cooked through. Serve with more Parmesan cheese on top.