In a pot over medium heat, cook the sausage until brown, breaking it into small crumbly pieces as it's cooking. Towards the last minute or two of browning add the minced garlic. Remove from heat. Drain the sausage of any liquid or grease that may have accumulated.
Add the 2 jars of marinara and the 1 cup of water to the sausage bowl. Stir in the 1 tablespoon Italian seasoning. Taste, and season with salt and pepper. This will be referred to as "the sauce." Set aside.
In a small bowl combine the ricotta, parsley, and Italian seasoning. Set aside.
Coat the inside and the sides of a large crock pot with nonstick cooking spray. Begin layering starting with the sauce. Being sure to add about 2 cups of the sauce to the bottom of the crockpot. Then top the sauce with noodles. Breaking the noodles if they don't fit, so that it covers all of the sauce.
Add a thin layer of ricotta atop the lasagna noodles. Generously sprinkle the shredded cheeses overtop the ricotta. Repeat these layers until all ingredients are used and it fills your crock pot. (Sauce, noodles, ricotta, cheeses, sauce noodles, ricotta, cheeses etc.) Ending with the shredded cheeses at the top.
Cook on high for 4 hours. Serve warm with a sprinkling of fresh parsley.