Mix together first nine ingredients thoroughly. Shape into large balls (larger than a golf ball, smaller than a tennis ball) and place in a sprayed jelly roll pan. Bake in a 350 degree oven for 25 minutes until well browned.
Remove meatballs from oven, drain grease off and place meatballs in 4 quart crock pot. Pour over spaghetti sauce and cook on low for 4 hours.
When ready to eat, open hoagie buns and spray with a bit of butter flavored cooking spray and toast under the broiler for 3-5 minutes until browned.
Remove buns from oven. Place two meatballs into each bun and spoon over sauce. Sprinkle generously with mozzarella cheese and place back under broiler for a few minutes or just until cheese is nicely melted. Serve immediately.