Cook pasta al dente (do no overcook) according to directions on the box. Strain pasta and add back to pasta pot, set aside.

Preheat oven to 350 degrees F.

Place a large skillet on the stovetop, add oil and heat 30 seconds over medium heat. Add Italian sausage and cook for 5 minutes while breaking apart with a spatula. Sauté until mostly cooked through, about 2 more minutes. Slide sausage to the side of the skillet, add chopped onion, minced garlic, and seasonings and cook for 3 more minutes while sautéing. Remove from heat and set aside.

Add the sausage mixture into the pot with the pasta, half of the shredded mozzarella cheese, and marinara sauce; mix to combine.

Add the mixture to a greased oven-safe casserole dish, then top with the remaining mozzarella and parmesan cheeses and sprinkle a bit of additional dried oregano and basil.

Place Mostaccioli in the oven and cook for 20 minutes. Switch the oven to broil, then broil for 3-5 minutes, watching closely so the cheese doesn’t burn. Carefully remove. Top with fresh basil and serve!