Grease your slow cooker well and set aside. In a large skillet heat the olive oil over medium heat. Once hot, add the onions and the beef. Cook and break up the beef until it is no longer pink. Drain any excess fat, if needed.
Stir in the garlic and let it cook until fragrant, just a minute or so. Then stir in the diced tomatoes, tomato sauce, water, sugar and seasonings. Let this simmer for 5-10 minutes just to let the flavors meld together. Then remove it from the heat and set aside.
In a large bowl, mix the ricotta, egg, seasonings, mozzarella cheese and parmesan cheese. Set that aside.
In the bottom of the slow cooker, spread about 1 cup of sauce...more if needed to completely coat the bottom. Place 2-3 of the lasagna noodles over the meat sauce, breaking them up to fit as best you can.
Place about a third of the ricotta mixture over the noodles and spread it all over.
Repeat this process. I get 3 layers altogether. After the last layer of ricotta mixture, spread over the last of the meat sauce. Top with the 1 cup of mozzarella cheese and the 1/2 cup of parmesan cheese. At this point you could always place the lid on and store it in the fridge until ready to cook.
Cook on low for 4-6 hours, or until the noodles are tender. Then scoop it out the best you can and serve immediately.
