Pizza Casserole

3 cups uncooked spiral pasta
2 pounds ground beef
1 medium onion, chopped
2 cans (8 ounces each) mushroom stems and pieces, drained
1 can (15 ounces) tomato sauce
1 jar (14 ounces) pizza sauce
1 can (6 ounces) tomato paste
1/2 teaspoon sugar
1/2 teaspoon garlic powder
1/2 teaspoon onion powder
1/2 teaspoon dried oregano
4 cups (16 ounces) shredded part-skim mozzarella cheese, divided
1 package (3-1/2 ounces) sliced pepperoni
1/2 cup grated Parmesan cheese

Directions:
Cook pasta according to package directions. Meanwhile, in a Dutch oven, cook beef and onion over medium heat until meat is no longer pink; drain. Stir in the mushrooms, tomato sauce, pizza sauce, tomato paste, sugar and seasonings. Drain pasta; stir into meat sauce. Divide half of the mixture between two greased 11-in. x 7-in. baking dishes; sprinkle each with 1 cup mozzarella cheese. Repeat layers. Top each with pepperoni and Parmesan cheese. Cover and bake at 350° for 20 minutes. Uncover; bake 10-15 minutes longer or until heated through. Yield: 2 casseroles (8 servings each).