1. Boil a large pot of salted water and cook the pasta until just al dente. Drain and set aside.

2. In a large skillet, heat olive oil over medium heat. Add chopped onion and cook until soft, about 5 minutes. Stir in garlic and cook for another 1 minute.

3. Add pumpkin puree, diced tomatoes (with juice), broth, oregano, nutmeg, salt, and pepper. Simmer for 10 minutes until thickened slightly. Stir in cream and remove from heat.

4. Preheat oven to 375°F. In a large mixing bowl, combine cooked pasta with the pumpkin-tomato sauce and mozzarella and Parmesan cheeses. Mix until fully coated.

5. Pour the pasta mixture into a greased baking dish. Sprinkle with cheddar cheese (if using). Bake for 20-25 minutes until bubbly and golden on top.