Prepare the sauce by melting the butter in a large pot over medium-high heat.
Once the butter is melted, add the spinach.
Saute for 2-3 minutes then add the garlic and sauté for an additional minute.
Next add the milk, salt, pepper, parmesan, ricotta and asiago cheeses.
Whisk well and simmer on low for 15-20 minutes while preparing the pasta.
Begin by boiling a large pot of water and cooking the pasta for app. 10 minutes or just before al dente.
In a small bowl combine the mozzarella, parmesan, asiago, ricotta, basil, oregano and parsley.
Fill a pastry bag or Ziploc bag with with the cheese herb mixture. If you have a piping tip that’s the easiest way to do it. If not, simply cut a small hole in the corner of the bag.
Pipe the cheese mixture into the rigatoni pasta.
Pour half of the Spinach Alfredo Sauce into the bottom of an oven-safe baking dish.
In a circular motion, add the filled pasta noodles to the dish.
Pour the remaining sauce on top.
Grate on a little extra parmesan cheese.
Bake for 25-30 minutes.
Notes
I do not recommend freezing this recipe. Since the sauce is milk-based, it will separate when frozen.
Leftovers of the stuffed rigatoni can be stored in the refrigerator for up to 4 days. The leftovers can be reheated in a covered baking dish in the oven at 350°F for 15-20 minutes. Or on a plate in the microwave for 2-3 minutes.
If rigatoni can not be found, you can use ziti pasta. But just know that it will be slightly smaller and harder to fill. You could also use manicotti, which are much larger than rigatoni, but delicious when filled and cooked in a creamy sauce.
Do NOT use “stand and fill” Ziplock bags for piping the cheese mixture into the rigatoni. The bottom of the bag has a fold that allows it to stand for filling. This will inhibit you from being able to make a clean cut in the corner of the bag to pipe out the cheese filling.