Preheat the oven to 350 degrees. Cut each slice of white American cheese into 4 squares. Cut each of the Hawaiian rolls in half and set aside.
Place a slice of the turkey and 2 of the cheese squares onto the top of the bottom half of each slider roll. Place the tops onto the rolls. Place the prepared sliders into the bottom of a large baking dish (you may need more than one depending on how many sliders you have).
Place the melted butter into a medium bowl. Whisk in Worcestershire sauce, Dijon mustard, dried minced onion, garlic powder, and poppy seeds. Whisk until the mixture is smooth. Pour the sauce evenly over the tops of all of the sandwiches in the baking dish. Allow sitting for 10 minutes or until the butter slightly sets.
Cover the baking dish with foil and place into the oven and bake at 350 degrees F. for 10 minutes or until the cheese has melted. Uncover and bake for an additional 2 minutes until the tops are slightly browned and crisp. Serve warm.