Start a large pot of water for the pasta, bring to a rolling boil and then cook pasta to just under al dente according to package instructions. Drain and drizzle with a touch of olive oil to prevent it from sticking together.
While the pasta cooks, heat a skillet to medium-high heat and add olive oil. When olive oil is hot and glistening, add the onion and sauté until they start to become translucent.
Add the Italian sausage and break down into smaller pieces and brown. Internal temperature should reach 165°F. When cooked, drain any excess grease and set aside.While the sausage cools,
In a large bowl, combine the ricotta, egg, 2 cups mozzarella, parmesan, chopped basil, seasoning and garlic. Stir the cheese mixture well to combine.Add the cooked pasta and browned Italian sausage to the cheese mixture when it is all cooked.
Lightly spray the bottom of a 9x13 inch baking pan with oil. Add about 2 cups of marinara to the bottom of the pan and spread to allow it to cover the bottom completely .Add the pasta mixture to the pan and spread evenly.
Cover the pasta with remaining 2 cups of marinara sauce. Sprinkle over the remaining shredded mozzarella cheese. Cover with aluminum foil and bake in 375°F preheated oven for about 20 minutes and then remove the foil and bake another 10 minutes uncovered or until cheese is melted and pasta is bubbling.
You can broil on high for the last 2-3 minutes for that golden brown topped melty cheese if desired.Allow to cool for 10 minutes and top with more freshly chopped basil before serving.