Step 1: Preheat your oven to 375°F (190°C). Prepare a 9x13 inch baking dish by spreading a thin layer of marinara sauce across the bottom.
Step 2: Wash the banana peppers and cut a slit down the length of each. Carefully remove the seeds and membranes, being mindful of the oils.
Step 3: In a skillet over medium heat, cook the Italian sausage until browned and crumbled. Drain any excess fat and let it cool slightly.
Step 4: In a medium bowl, combine the cooked sausage, cream cheese, provolone, Parmesan, minced garlic, parsley, and black pepper. Mix until well combined.
Step 5: Stuff each banana pepper generously with the sausage mixture and place them in the prepared baking dish.
Step 6: Bake for 25-30 minutes, or until the peppers are tender and the cheese filling is golden and bubbling.
Step 7: Serve warm, optionally topped with more fresh parsley or a drizzle of extra marinara.