Mix ground chicken and Italian bread crumbs together thoroughly. Roll the mixture into balls, weighing 2.5-3 ounces each.
Preheat your Blackstone griddle to high heat.
Pour marinara sauce into a cast iron pan on the hot griddle top, stirring occasionally as it warms up.
Melt butter and Italian seasoning in another, smaller cast iron pan on the griddle top.
Drizzle and spread cooking oil on the griddle top. Place each meatball on the griddle and top with a piece of parchment paper. Flatten with a spatula or Blackstone Burger Press tool.
Cook for 2-3 minutes on each side, until nicely seared and cooked through.
Place one piece of provolone cheese on 4 of the patties and then top with the second patty.
Spread the melted butter and herb mixture on the inside surfaces of brioche buns. Toast buns on the griddle top, butter sides down. Remove when browned as desired.
Top each double-burger with about 1 tablespoon of Parmesan cheese and about 1 tablespoon of warm marinara sauce.
Place the bottom halves of each bun on a serving platter. Add more marinara sauce and Parmesan cheese if desired, then top with the patties, marinara, fresh basil, pepperoncini (if desired), and the top halves of the buns. Enjoy!
