Creating Irresistible Baked Italian Sub Sandwiches is simple if you follow these straightforward steps:

1. Preheat Oven: Begin by preheating your oven to 375°F (190°C).
2. Prepare the Rolls: Slice the hoagie rolls in half lengthwise, leaving one edge intact to create a pocket for the fillings.
3. Mix the Spread: In a small bowl, combine mayonnaise and Italian dressing. Mix well.
4. Spread on Rolls: Generously spread the mayonnaise mixture on the inside of each hoagie roll.
5. Layer the Meats: Start layering the sliced salami, ham, and pepperoni evenly inside each roll.
6. Add Cheese and Veggies: Place slices of provolone cheese on top of the meats, followed by the black olives, green bell pepper, and red onion.
7. Season: Sprinkle the grated Parmesan cheese, dried oregano, garlic powder, salt, and pepper over the fillings.
8. Close the Rolls: Carefully press the top half of the rolls down to secure the fillings.
9. Wrap in Foil: Wrap each sandwich tightly in aluminum foil to keep them warm and help the cheese melt evenly.
10. Bake: Place the wrapped sandwiches on a baking sheet and bake in the preheated oven for 15-20 minutes, or until the cheese is melted and bubbly.
11. Slice and Serve: Once done, remove from the oven, unwrap, and slice each sandwich in half for easy serving.

These steps will guide you in creating these incredible sandwiches effortlessly!