Coat microwave-safe baking dish with cooking spray.
Cook rigatoni according to package directions until al dente. Do not overcook. Drain rigatoni; rinse.
Tightly roll 2 slices pepperoni into tight cylinder. Stuff 1 piece rigatoni with pepperoni. Place in baking dish. Repeat with remaining pepperoni and rigatoni. Pour pasta sauce over filled shells.
Microwave rigatoni mixture on MEDIUM-HIGH (75%) 5 minutes or until hot and steamy.