Chop up onion. Pour olive oil in a large skillet and cook onion 5-7 mins.
Add ground beef and minced garlic to the skillet. Cook about 10 mins, until meat is no longer pink.
Drain grease. Add salt, pepper, Italian seasoning and rosemary. Mix.
Add pasta sauce, diced tomatoes and sugar. Mix.
Simmer for 5-7 mins.
Once the pasta is cooked, drain water and add the sauce mixture to the pasta pot. Mix together.
Using a 9″x13″ deep casserole dish, layer in the following order:
1/2 pasta sauce mixture,
Evenly dollop the ricotta cheese,
1 cup mozzarella cheese,
1/2 cup parmesan cheese,
1/2 pasta sauce mixture,
1 cup mozzarella cheese,
1/2 parmesan cheese.