16 oz. box rotini
1 lb. bulk Italian sausage
2 14.5 oz. cans diced tomatoes
6 oz. can tomato paste
2 cups shredded mozzarella cheese
Meanwhile, in large skillet or Dutch oven, cook sausage over medium heat until no longer pink; drain. Stir in tomatoes, including juice, and tomato paste. Bring to a boil. Reduce heat, cover, and simmer for 5 minutes. Remove all but approximately 1/2 cup of sauce to a bowl.
Drain pasta. Place half over the sauce in the pan. Layer with half of the reserved sauce and 1 cup of the cheese. Repeat with remaining pasta, sauce, and cheese. Cover and cook over low heat for 10 minutes.