Heat oven to 375. Cook and drain noodles as directed on package. Cook beef, onion, cilantro and chili powder in 10 inch skillet over medium heat. Stir occasionally til beef is brown; drain. Put 5 of the noodles in bottom of 13 x 9 inch pan. Layer with 1 1/2 cups of beef mixture, 1 cup of ricotta cheese and 1 1/4 cups of the salsa. Repeat with remaining noodles, beef mixture, ricotta cheese and salsa. Sprinkle with Monterey Jack cheese. Bake uncovered, 35 to 40 minutes or until hot. Let stand 10 minutes before cutting.