This is a keeper, and you won't believe how easy it is to prepare. It is so good! I made it gluten-free, but you can use regular pasta. Be sure to follow the recipe as written because the cooking foil technique is unusual but necessary to get the pasta texture you want but baked in the slow cooker. Enjoy, my friends!
Make TWO foil collars from two 18 inch sheets of tin foil, folded in half to make each sheet about 5 inches wide and 18 inches long. This will go around the perimeter of the slow cooker, twice. See my photo, one is inside the other. This technique will prevent the ziti from scorching and help it cook more evenly and keep its shape, so don't omit.
This makes four layers of foil between your ziti and the wall of the slow cooker. there will be no foil on the bottom of the slow cooker.
Spray generously with Pam inside the foil "walls".
Heat oil in large Dutch oven. Remove the casings from the sausage and using a spoon, break it into small pieces. Fry over medium high heat until well browned. Add onion and cook until lightly browned, about five minutes, then add the garlic, sugar, oregano, salt and pepper. Cook 2 minutes.
Measure the raw ziti and add it to the meat mixture. Turn it constantly for five minutes until the edges of the pasta become translucent. Turn off the fire. Note: This technique of cooking the ziti in oil and meat prevents uneven cooking of the pasta, so don't omit.
Add the crushed tomatoes and the tomato sauce. Scrape up any brown bits. Mix well.
Carefully spoon the sauce into the center of the foil-lined slow cooker.
It will look like this.
Add the lid, cover and cook on low about 3 hours.
Mine was perfectly done at 3 hours. So you will want to check yours at about 2 1/2 hours.
Now it is cooked. Using tongs, remove the foil sleeves from the walls of the slow cooker.
Dollop ricotta over the ziti in the slow cooker.
Sprinkle the grated mozzarella over the ziti and ricotta. Put the lid on the slow cooker for 20 minutes on the warm setting just to melt the cheeses.
Here is how the Ricotta and Mozzarella cheeses look when melted.