1Heat oven to 375°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray. Cook and drain macaroni as directed on package, using minimum cook time. Return to saucepan; cover to keep warm.
2Meanwhile, in 2-quart saucepan, heat whipping cream, mustard, salt and red pepper to boiling. Reduce heat; stir in Cheddar cheese with wire whisk until smooth. Pour sauce over macaroni; stir until well coated. Stir in tomatoes and onions. Pour into baking dish.
3In small bowl, mix Parmesan cheese and bread crumbs. Stir in oil. Sprinkle over macaroni mixture.
4Bake uncovered 15 to 20 minutes or until edges are bubbly and top is golden brown.