Prepare ziti according to package directions; drain and return to pot.
Stir together Alfredo sauce and sour cream; toss with ziti until evenly coated. Spoon half of mixture into a lightly greased 13- x 9-inch baking dish.
Stir together ricotta cheese and next 3 ingredients; spread evenly over pasta mixture in baking dish. Spoon remaining pasta mixture evenly over ricotta cheese layer; sprinkle evenly with mozzarella cheese.
Bake at 350° for 30 minutes or until bubbly.
Ziti pasta is shaped in long, thin tubes; penne or rigatoni pasta may be substituted, if desired.