In a large bowl combine the ground turkey, Italian breadcrumbs, eggs, Italian seasoning and salt. Mix well with clean hands.
Using a medium cookie scoop (about 1-1/2 tablespoons), form equal size meatballs and set aside.
Pour 1 cup of sauce into the bottom of the crockpot and spread evenly. Lay the meatballs on top of the sauce (it's okay if the meatballs need to be stacked.)
Pour the rest of the sauce over the meatballs.
Set for 2 hours on high, stirring halfway through.
When meatballs are done, line a sheet pan with the split sub rolls and fill each sub roll with 3 meatballs and sauce.
Top with shredded mozzarella cheese and bake for 5 minutes in the oven at 350F or broil to simply melt the cheese.
Sprinkle with fresh parsley (optional) and serve.
Notes
You can cut this recipe in half to serve less people, cooking time may need adjusting. This is a great recipe to freeze for later though.
If you wan't to make the subs larger, you can find larger sub rolls and make the meatballs larger.
If you don't like mozzarella then parmesan and provolone are great substitutions.