Preheat oven to 375°F. Coat a 2-quart shallow baking dish with cooking spray. Cook pasta as directed. Drain. Set aside. In bowl, combine ricotta, parmesan and parsley. Reserve. In another bowl, stir together marinara sauce and tomato paste, reserve 1 cup. Toss pasta with remaining sauce mix.
Spread half of pasta mix in baking dish. Quarter each slice of mozzarella. Arrange half of pepperoni, half of ricotta mix and half of mozzarella mix over pasta in baking dish. Add remaining pasta mix, top with reserved 1 cup sauce mix, then remaining pepperoni, ricotta and mozzarella. Coat sheet of foil with cooking spray. Cover baking dish with foil, coated side down.
Bake until hot and bubbly, about 40 min. Uncover, bake until cheese is lightly browned, 10 min. Let stand 15 min before serving.