Heat oil on medium in a 12 inch skillet. Add onion and salt and cook until the onion just starts to brown, (6 minutes)
Stir in garlic, oregano and red pepper flakes. cook 30 seconds.
Add ground, bulk sausage and cook until no longer pink, (4-5 minutes).
Add pasta pieces on top of the meat.
Cover pasta with tomatoes and tomato sauce and 4 oz water, reduce heat to simmer and cover the skillet.
Stir occasionally until the pasta is cooked through, (20 minutes)
Remove from heat and stir in Parmesan cheese then sprinkle with mozzarella and place heaping tablespoons of ricotta on the sauce. Cover for 5 minutes. Sprinkle with the chopped basil then serve.
Notes
Use whole milk ricotta cheese. I find that the low-fat kind often has a grainy texture.
Store leftovers in a covered container in the refrigerator for up to 3 days.