Preheat oven to 350 degrees.

Cook spaghetti a minute shy of al dente and drain.

In large bowl, stir together yogurt, ricotta, half and half, 1/2 cup Parmesan cheese, mozzarella cheese, oregano, basil, pepper, and salt. Add spaghetti and toss until well coated.

Pour mixture into 9x13 pan lightly sprayed with cooking spray. Before covering dish with aluminum foil, spray the Spagansa side lightly with cooking spray to prevent cheese from sticking. Bake for 30 minutes.

While pasta is baking, brown Italian sausage with the onion. Drain set aside. In same skillet, add olive oil, garlic and a pinch of salt over low heat. Cook until garlic becomes fragrant. Add crushed tomatoes and pepper flakes and increase heat to medium for two minutes. Return to low simmer and stir in remaining Parmesan cheese and sausage.

After baking, remove pasta from oven and top with meat sauce. Allow to sit for 10 minutes before cutting into squares to serve.