In a large bowl, combine the ground beef, bread crumbs, egg, Italian seasoning, garlic powder, salt, and pepper. Shape into 1-inch balls and place in the slow-cooker.
Pour the marinara sauce over the meatballs and cover the slow-cooker. Cook on low for 5-6 hours.
Break the spaghetti into thirds and add to the slow-cooker. Stir the spaghetti into the sauce and cook on low for an additional 30 minutes.
Sprinkle with Parmesan cheese before serving.
Interesting Facts
The origin of spaghetti and meatballs is unknown but it's believed to have originated in the United States.
The sauce used in spaghetti and meatballs is typically a marinara sauce, but other sauces such as Alfredo can be used.
The traditional Italian way of eating spaghetti and meatballs is to serve the meatballs over the spaghetti, not mixed together.