Perfect Meatballs and Spaghetti

ground meat (see note up top for suggestions)

panko-style breadcrumbs

milk, any kind

finely chopped parsley, plus more to serve

finely grated parmesan or pecorino romano cheese, plus more to serve

coarse or kosher salt, divided

Red pepper flakes and/or freshly ground black pepper

onion powder

large eggs

garlic cloves, minced, divided

olive oil

of crushed tomatoes

dried spaghetti