Preheat oven to 350 degrees. Lightly spray a sheet pan with non-stick cooking spray or line with a sheet of parchment paper. Set prepared pan aside.
Using a long bread or serrated knife, slice the Hawaiian rolls horizontally, in the middle of the rolls. Place the bottom portion of the rolls on the pan, and set the top portion of the rolls off to the side.
In a mixing bowl, add the cooked chicken. Pour the ranch dressing over the top of the chicken, and stir together to coat with a rubber scraper. Add the coated chicken on to the bottom portion of the bread on the pan.
To the top of the chicken, sprinkle on the bacon pieces. Add the cheese slices. Bake the bottom portion with the chicken, bacon and cheese for 10 minutes at 350 degrees. (You won't add the top portion of the bread yet.)
Mix the butter topping. In a small bowl, combine the melted butter, parsley, onion powder and garlic powder. Mix with a fork or mini whisk. Set aside.
Once the bottom portion of the sliders have baked for 10 minutes, remove from the oven. Place the top portion of the bread onto the baked bottom portion. Brush the top of the rolls with the butter mixture. Sprinkle the top with the Parmesan cheese. Return to the oven and bake for another 10 minutes.
Slice and serve while hot. Enjoy!