Preheat oven to 400°F. Place rolls (keep them attached) on a cutting board. Using a serrated knife, cut rolls in half lengthwise (without breaking rolls apart). Open rolls and place tops on one side of a baking sheet and bottoms on the other side, cut-side up.
Melt butter in a small microwave-safe bowl, then stir in garlic powder. Brush butter on insides of top and bottoms of bread. Bake bread for 8-10 minutes, or until bread is lightly golden brown.
Prepare chicken by slicing the thickest part of the breast about ½” thick. Cut the thinner part of the breast into pieces slightly larger than the individual rolls.
Meanwhile, warm a large skillet over medium-high heat. Drizzle with olive oil. Sprinkle chicken with ½ of salt and ½ of pepper. Cook until browned, flip and cook until cooked through, about 8 minutes total.
Remove bread from oven. Carefully remove top halves of rolls and place on a plate. Set aside. Sprinkle Parmesan cheese over the bottom halves. Top with cooked chicken pieces. Drizzle each chicken piece with about 1 tablespoon of marinara sauce and top with mozzarella cheese. Bake 5 minutes or until cheese is bubbly and melted.
Place top halves back on chicken. Cut into sliders, serve and enjoy!
