In a large mixing bowl, stir together the parmesan, bread crumbs, garlic powder, oregano, parsley, salt, pepper, and egg. Add the ground turkey to the bowl and mix everything until combined. (Don't overmix.)
Using a measuring spoon, portion the turkey mixture into 2 tablespoons scoops. Holding the scoop of turkey in your hand and press a mozzarella cube into the center. Then use your hands to wrap the turkey around the cheese (sealing it inside) and form a meatball.
Place a large skillet over medium heat and pour in half of the olive oil. Once the oil is hot, place some meatballs in the skillet. Cook until browned on all sides, turning the meatballs as needed. (You will need to cook in batches so the skillet is not overcrowded. Add more oil to the skillet before the second round.)
Take the skillet off the heat andy drain any excess grease. Add all the meatballs to the skillet and then pour in half of the marinara sauce. Stir to coat the meatballs in sauce.
Place the bottom half of the slider rolls into a 9-inch x 13-inch baking dish or large baking sheet. Spread 1/2 tablespoon of marinara on the bottom of each bun, please one meatball on each bun, and then top with 2 quarter pieces of mozzarella.
Place the top half of the slider rolls over the filling. Brush the tops of the rolls with melted butter and then sprinkle with garlic powder and Italian seasoning.
Bake for 15 minutes until the cheese is melted and the rolls are golden brown. Remove from the oven and serve warm.
Notes
If you can't find pre-seasoned ground turkey, add 1/2 teaspoon Italian seasoning and 1/2 teaspoon paprika to the turkey mixture.
Once the meatballs are cooked you can cool them and then store in the fridge or freezer in an airtight container for later.