Turkey meatballs in marinara on a toasted sub — it's a lighter take on the classic but doesn't sacrifice any of that meatball sub satisfaction.
Preheat your oven to 400°F. Line a baking sheet with parchment for easier cleanup.
In a large bowl, combine ground turkey, breadcrumbs, egg, parsley, Parmesan, garlic powder, onion powder, oregano, salt, and pepper. Mix until just combined — don't overwork to keep meatballs tender.
Form the mixture into 16 equal-sized meatballs and arrange them evenly on the prepared baking sheet.
Bake the meatballs at 400°F for 12 minutes, then transfer them into a simmering saucepan of marinara sauce. Simmer gently, covered, for 8 minutes to cook through and infuse flavor.
Slice the sub rolls lengthwise (do not cut all the way through), toast them cut-side up under a broiler until lightly crisp, then fill each roll with 4 meatballs and a generous spoon of sauce.
Top each sub with shredded mozzarella. Broil on high for 2-3 minutes just until cheese is melted and golden. Serve hot.