Step 1

Add the ground beef, Italian sausage, beaten egg, breadcrumbs, Parmesan, onion powder, garlic powder, and salt to a bowl. Use your hands to combine the ingredients until they are evenly mixed. Divide the mixture into four equal portions, then shape each into a ball.

Step 2

Place the meatballs in the slow cooker and pour the marinara over top, making sure to coat the top of each meatball. The sauce will only come up about half way to the top of the meatballs, but that's okay. The slow cooker will fill with steam, which will help cook the meatballs even though they are not completely submerged.

Step 3

Place the lid on the slow cooker and then cook on high for 3 hours, or low for 6-7 hours. Use an instant read thermometer to make sure the meatballs have reached at least 160ºF on the inside (mine had exceeded this temperature after 3 hours on high).

Step 4

Near the end of the cook time, cook the spaghetti according to the package directions, and then drain in a colander.

Step 5

Remove the cooked meatballs from the slow cooker, then add the cooked and drained spaghetti, and toss it to coat in the sauce. Divide the sauced spaghetti between four plates, add one giant meatball to each, then enjoy.