Step 1: Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish so the pasta doesn’t stick.
Step 2: Bring a large pot of salted water to a boil and cook the pasta 2 minutes less than package instructions. This way, it will finish cooking in the oven without turning mushy. Drain and set aside.
Step 3: In a large skillet, heat the olive oil over medium heat. Add the chopped onion and cook until softened, about 5 minutes. Stir in the garlic and cook for 1 minute until fragrant.
Step 4: Add the pumpkin puree, marinara sauce, Italian seasoning, smoked paprika, salt, and pepper. Stir well and let the sauce simmer for about 5 minutes. If it feels too thick, stir in broth a little at a time until it reaches your desired consistency.
Step 5: Add the cooked pasta to the sauce and stir until every piece is coated. Pour the mixture into your prepared baking dish and spread it evenly.
Step 6: Sprinkle the mozzarella, cheddar, and Parmesan evenly over the top. Bake uncovered for 20–25 minutes, or until the cheese is melted, bubbly, and golden in spots. Garnish with fresh parsley or basil before serving.