Pulled Pork Casserole

1 (24 oz.) container refrigerated mashed potatoes, warmed
1 c. frozen corn, thawed
1 1/2 c. shredded Cheddar cheese, divided
1/4 c. sliced scallions, divided
1 (18 oz.) container refrigerated barbecued pulled pork
1 c. coarsely crushed potato chips

In medium bowl combine mashed potatoes, corn, 1 cup cheese and 2 tablespoons scallions; mix well. Spoon mixture into 7-inch by 11-inch baking dish coated with cooking spray. Evenly spoon pork over potatoes. Sprinkle with remaining cheese, scallions and crushed potato chips. Bake in preheated 375° oven 25-30 minutes or until casserole is heated and chips are golden.