Warm up a tablespoon of olive oil in a large skillet on medium-high heat.Add the sausage and the ground meat to the pan,break lumps up with a fork, and brown for a few minutes, stirring occasionally.
Add in chopped onion, grated garlic, Italian seasoning, red pepper flakes, salt, blackpepper, and cook for 4 minutes, stirring occasionally.
Pour in the marinara sauce and simmer for 5 minutes. Turn the heat off, stir in the basil, then taste and adjust for salt.Important: set aside 3 cups of sauce and keep the remaining sauce in the skillet! You'll need 1 cup of sauce for the bottom of the baking dish and 2 cups on top of the pasta.
COOK THE PASTA
Cook 1 pound of pasta in 1 gallon of boiling water with 2 tablespoons of salt. Cooking time should be as instructed on the package minus 3 minutes.Note: If the package says 10 minutes, cook the pasta for 7. That's because we want the pasta much harder than "al dente" since we finish cooking it in the oven.
Reserve one cup of pasta water, then drain the pasta, and toss it in the sauce until thoroughly coated (off the heat).
BUILD THE DISH
Preheat the oven to 350°F or 180°C. Cover the bottom of the baking dish with 1 cup of reserved tomato sauce. Then add 6 dollops of ricotta cheese (about ½ cup of ricotta).
Add in the pasta and arrange it evenly across the baking dish.Drizzle with 4 tablespoons of reserved pasta water.
Cover with the reserved 2 cups of tomato sauce, then with the remaining ricotta, grated parmesan, and shredded mozzarella cheese.
Bake at 350°F or 180°C for 20 minutes, or until the cheese melts and browns. Let sit out of the oven for 10 minutes before serving it.