Begin by preheating your oven to 375°F (190°C). Prepare your baking sheet by lining it with parchment paper or a silicone mat.

Carefully slice the Italian sub rolls in half lengthwise, keeping them hinged at the bottom. Arrange the opened rolls cut side up on the prepared baking sheet.

In a small mixing bowl, melt the unsalted butter, then stir in garlic powder, onion powder, dried oregano, dried basil, red pepper flakes, salt, and black pepper.

Generously brush the seasoned butter over the cut sides of the rolls. Ensure even coverage.

Layer the deli-sliced salami on the bottom half of each roll, then add a slice of ham and a layer of pepperoni.

Sprinkle mozzarella cheese over the meats, followed by provolone cheese and grated Parmesan cheese.

Scatter the roasted red peppers, sliced black olives, banana peppers, and fresh basil leaves atop the cheese.

Place the loaded baking sheet in the preheated oven and bake for 10-12 minutes.

Once baked to perfection, remove the sandwiches from the oven and let them cool for a few minutes before slicing and serving.