Follow these simple steps to create the Cheesy Chicken Garlic Bread Sandwich:

1. Preheat the Oven: Begin by preheating your oven to 375°F (190°C).
2. Prepare the Chicken Mixture: In a large bowl, combine the shredded chicken, mozzarella cheese, cream cheese, mayonnaise, garlic powder, parsley, salt, and pepper. Mix until well combined.
3. Assemble the Sandwich: Take four slices of garlic bread and spread a generous amount of the chicken mixture on each slice. Top with the remaining four slices of garlic bread to form sandwiches.
4. Coat with Parmesan: Sprinkle grated Parmesan cheese generously on top of each sandwich for an extra cheesy finish.
5. Bake the Sandwiches: Place the assembled sandwiches on a baking sheet and bake in the preheated oven for 15-20 minutes, or until the bread is golden and crispy.
6. Cool Slightly: Remove from the oven and let the sandwiches cool for a minute before slicing.
7. Serve Warm: Cut the sandwiches in half and serve while warm, allowing the gooey cheese to stretch with each bite.

With these straightforward instructions, you’ll be able to whip up the Cheesy Chicken Garlic Bread Sandwich in no time!