Slow Cooker Lasagna

1 pound hamburger
1 medium onion, chopped (1/2 cup)
3 cans (15 ounces each) Italian-style tomato sauce
2 teaspoons dried basil leaves
1/2 teaspoon salt
2 cups shredded mozzarella cheese (8 ounces)
1 container (15 ounces) part-skim ricotta cheese
1 cup grated Parmesan cheese
15 uncooked lasagna noodles

Cook hamburger and onion in 10-inch skillet over medium heat 6 to 8 minutes, stirring occasionally, until hamburger is no longer pink; drain.
Stir in tomato sauce, basil and salt.

Mix 1 cup of the mozzarella cheese and the ricotta and Parmesan cheeses. (Refrigerate remaining mozzarella cheese while lasagna cooks.)

Spoon one-fourth of the hamburger mixture into 6-quart slow cooker; top with 5 noodles, broken into pieces to fit.

Spread with half of the cheese mixture and one-fourth of the hamburger mixture.

Top with 5 noodles, remaining cheese mixture and one-fourth of the hamburger mixture.

Top with remaining 5 noodles and remaining hamburger mixture.

Cover and cook on Low heat setting 4 to 6 hours or until noodles are tender.

Sprinkle top of lasagna with remaining 1 cup mozzarella cheese.

Cover and let stand about 10 minutes or until cheese is melted.

Cut into pieces.