Preheat oven to 375°F (190°C). Grease a 9x13-inch baking dish.
Cook pasta in salted water until just al dente. Drain and set aside.
In a large skillet, heat olive oil and brown the sausage. Remove and set aside.
In the same skillet, sauté onion until soft. Add garlic, oregano, and red pepper flakes. Cook 1 minute more.
Stir in crushed tomatoes and simmer 10 minutes. Add cream and return sausage to the pan. Simmer 5 more minutes.
Combine pasta and sauce. Stir to coat evenly. Add a splash of pasta water if needed.
Layer half the pasta in the baking dish. Sprinkle with half the mozzarella and Parmesan. Repeat with remaining pasta and cheeses.
Cover with foil and bake 20 minutes. Uncover and bake an additional 10–15 minutes until cheese is bubbly and golden.
Rest for 5 minutes. Garnish with basil and serve warm.