Got this recipe from a crockpot group i belong to on cafemom.
6 1/2 cups uncooked wide egg noodles
3 tablespoons butter
1 1/2 pounds ground beef
2 1/4 cups spaghetti sauce
6 ounces process cheese (eg. Velveeta), cubed
3 cups shredded mozzarella cheese
Cook noodles according to package directions; drain. Add butter; toss to coat.
In a large skillet, cook beef over medium heat until no longer pink; drain. Spread a fourth of the spaghetti sauce into an ungreased 5-qt. slow cooker. Layer with a third of the noodles, a third of the beef, a third of the remaining sauce and a third of the cheeses. Repeat layers twice.
Cover and cook on low for 4 hours or until cheese is melted and lasagna is heated through.