Lightly coat a 2-quart casserole with cooking spray; set aside. Place corn in a colander and thaw by running under cool water; drain. Set aside.
In a large saucepan cook sweet pepper and onion in 1 tablespoon hot butter until tender. Stir in corn and black pepper. In a medium bowl whisk together soup, cream cheese spread, and milk. Stir soup mixture into corn mixture. Transfer to prepared casserole.
Bake, covered, in a 375 degree F oven for 50 to 55 minutes or until heated through, stirring once.