In a large bowl, toss broccoli with oil; spread onto foil-covered rimmed baking sheet. Drizzle with water. Bake in a preheated 450-degree oven for 10 min. Meanwhile, cook pasta as directed on package, omitting salt.
Turn broccoli; sprinkle with 3/4 cup cheese mixture. Bake 10 min.
DRAIN pasta; place in large bowl. Add broccoli mixture; mix lightly. Top with 1/4 to 1/2 cup mozzarella, if desired.