Cook the pasta: Cook the bowtie pasta in a large pot of salted boiling water until al dente, according to package instructions. Drain and set aside.
Brown the sausage: In a large skillet, heat the olive oil over medium heat. Add the Italian sausage, breaking it up with a spoon, and cook until browned and cooked through, about 7-10 minutes.
Make the sauce: Stir in the marinara sauce and heavy cream, and bring the mixture to a simmer. Season with Italian seasoning, salt, and pepper.
Combine pasta and sauce: Combine the cooked pasta with the sausage and sauce mixture, ensuring the pasta is well coated.
Prepare for baking: Transfer the pasta mixture to a greased baking dish. Sprinkle the mozzarella and Parmesan cheeses evenly over the top.
Bake: Bake in the preheated oven at 375°F (190°C) for 20-25 minutes, or until the cheese is melted and bubbly.
Serve: Remove from the oven and let it cool slightly before serving. Garnish with fresh basil leaves if desired.
Enjoy this delicious and easy-to-make Baked Italian Sausage and Bowtie Pasta!