Cut a 20-inch piece of aluminum foil into 4 3-inch strips. Criss-cross strips across bottom and up sides of slow cooker. Spray with canola oil (or cooking spray).
Combine the bread crumbs, 1 cup spaghetti sauce, egg, onion, and seasonings. Crumble beef over mixture and mix well. Shape into a loaf; place in the center of the slow cooker.
Spoon remaining spaghetti sauce over meat loaf. Cover and cook on low for 3-4 hours or until a thermometer reads 160°. Using foil strips as handles, remove meat loaf to a platter.