Lasagna Casserole

This is from Families on the Go, a great freezer cookbook!  It is a great shake up from the traditional lasagna, but is still delicious! Enjoy!

Lasagna Casserole
1 1/2 lbs. ground beef, browned
1 medium onion, chopped
1 tsp. garlic powder
1/2 tsp. garlic salt
1 (14 oz) jar spaghetti sauce
1 (6 oz) can tomato paste
12 oz small pasta (shell, tube, egg noodle)
1 (16 oz) tub sour cream
1/2 c. shredded Parmesan cheese
3 c. shredded mozzarella cheese
In a skillet, combine browned beef, onion, garlic powder, and salt, spaghetti sauce, and tomato paste.  Simmer over medium heat for 15-20 minutes.  Cook pasta according to package directions.  Place half of the pasta in the bottom of a 9x13 inch pan.  Top with half of the meat sauce. Spread 1 cup sour cream on top and sprinkle with 1/4 cup Parmesan cheese.  Then sprinkle with 1 1/2 cups mozzarella cheese.  Repeat layers.  Cover and bake at 375 degrees for 45 minutes.  Uncover and bake for 10 more minutes.