Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the lasagna noodles, and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta is slightly tender but not cooked through, about 7 minutes. Drain well in a colander set in the sink.
Cook and stir ground beef in a large skillet over medium-high heat until beef is browned; drain, then stir in sauce. Set aside. Combine 2 cups of mozzarella cheese, Parmesan cheese, ricotta cheese, and eggs in a separate bowl.
Pour about 1/2 cup of the sauce mixture in the bottom of a slow cooker and cover with a layer of noodles. Sprinkle about 1/4 of the cheese mixture over the noodles, then ladle about 1/4 of the remaining sauce over the cheese. Repeat layering, ending with a layer of sauce and topping with the remaining 2 cups of mozzarella cheese. Cook on High setting for 2 to 3 hours, or on Low setting for 8 to 9 hours.
