In a medium high heat oiled pan, brown the Onions, Bacon, and Celery. It should take about 5 minutes.
Add in the Pumpkin Puree, Tomato Paste, Salt, Black Pepper, Garlic, Rosemary, and Stock into the pan. Turn the heat to low, mix everything together and simmer for at least 15 minutes to infuse the flavor. Turn off the heat, and let the sauce simmer for another 10 minutes.
Add in the Ricotta to the sauce and mix together
Add in the boiled Pasta, and Mozzarella. Fold it together until the Pasta is evenly coated with the sauce, and the Mozzarella has melted.
The sauce is to personal taste, so adjust the recipe based on what is desired.Boil more pasta if wanted.Add more water or stock in the sauce when it is simmering in case it gets too dry.After the first simmering, it is very important to turn off the heat and let the sauce cool down before adding the ricotta. This will ensure that the ricotta melts evenly and doesn’t seize or clump while being mixed into the sauce.