This was from a cookbook my Mom worked on right before she passed away. It was for the Clarkston Chamber of Commerce, so I doubt I will be arrested for copyright infringement for sharing it with you. It originally called for 12oz cottage cheese (gross) so I sub ricotta. You can change it back to cottage if you prefer.
1 1lb of ground turkey or beef
1 medium onion, chopped (I used a couple shakes of dried minced onion, and a few tsp of minced garlic)
1 jar of your favorite spaghetti sauce, approx 26 oz. (I used a 3lb jar of Prego)
15oz ricotta cheese
1/2 cup grated parmesan cheese
1 egg, beaten
12 oz lasagna noodles (not cooked)
12 oz shredded mozzarella (reserve 1/2 cup)
Brown meat and onion (and garlic) in skillet. Drain off fat. Add spaghetti sauce (and I added additional spices) and simmer for 5-10 minutes. If sauce is too thick add about 1/2cup of water to thin it (I did). In a separate bowl, combine the ricotta cheese, parmesan cheese, and mozzarella cheese (reserving 1/2 cup) and the egg (I also threw in pesto here). Mix thoroughly. Spoon a layer of meat sauce onto the bottom of the slow cooker. Add 2 layers of uncooked lasagna noodles (broken into pieces to make them fit). Top with cheese mixture, then sauce, then 2 layers of noodles, then cheese, then the remaining sauce. Sprinkle reserved 1/2 cup of mozzarella on very top. Cover and cook on low for 6-8 hours or on high for approx 3 hours.