Preheat your oven to 375°F (190°C).

Cook the pasta in boiling salted water until al dente, about 8-10 minutes. Drain and set aside.

Sauté diced onion in olive oil over medium heat until translucent, about 5 minutes. Add minced garlic and sauté for 1 more minute.

Mix in pumpkin puree, ricotta cheese, nutmeg, salt, and black pepper. Cook until smooth and creamy, about 2-3 minutes.

Gradually stir in broth to achieve desired consistency, letting it warm through.

Add fresh spinach to the sauce, stirring until wilted, about 2-3 minutes.

Combine the creamy sauce with the drained pasta in a large bowl.

Transfer the pasta mixture into a greased baking dish, smoothing the top.

Sprinkle mozzarella and Parmesan cheese over the top.

Bake in the preheated oven for 20-25 minutes, or until the cheese is melted and golden.

Let the dish rest for about 10 minutes before serving.

Serve portions garnished with basil or parsley if desired.