1. Prepare ziti according to package directions; drain and return to pot. 2. Stir together Alfredo sauce and sour cream; toss with ziti until evenly coated. 3. Spoon half of mixture into a lightly greased 13- x 9-inch baking dish. 4. Stir together ricotta cheese and next 3 ingredients; spread evenly over pasta mixture in baking dish. 5. Spoon remaining pasta mixture evenly over ricotta cheese layer; sprinkle evenly with mozzarella cheese. 6. Bake at 350° for 30 minutes or until bubbly.
