Mix together ricotta cheese, egg, garlic (I mince mine with my Microplane), oregano, basil, salt, and pepper.
Mix in the parsley, and most of the Parmesan. I reserve some to add to the top.
The key to making this work is to make sure that there is a lot of moisture. Put about 1 cup of sauce in the bottom of your slow cooker.
Lay 3 noodles over the sauce.
Add half of the cheese mixture.
Sprinkle a bit of the mozzarella over the ricotta cheese. This acts like glue when the cheese melts and holds everything together.
Add another layer of noodles and cheese. I add 3 more noodles to the top and more sauce.
I add a layer of paper towel before I put the lid on the slow cooker. It helps to keep the moisture off of the lasagna.
Cook on LOW for 4 to 5 hours. The noodles need to be soft.
Sprinkle the lasagna with the rest of the mozzarella and Parmesan.
And some more parsley. I think that it adds a lot of freshness. It is also how my mom makes lasagna, so that is what I do too. Cook until the cheese melts, about 20-30 minutes.
Let the lasagna stand for a few minutes before you cut it. It will hold together better and not fall apart.
Serve with some garlic bread and a simple salad.