Do the prep. Preheat the oven to 350°F or 177°C. Cut each slice ofcheese into 4 squares. Cut each of the Hawaiian rolls in half and set aside.
Assemble the sliders. 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.
Make the sauce. Place the melted butter into a medium bowl. Whisk in Worcestershire sauce, Dijon mustard, dried minced onion, garlic powder, and poppy seeds until the mixture is smooth. Pour the sauce evenly over the tops of all of the sandwiches in the baking dish. Let the sliders sit for 10 minutes.
Bake. Cover the baking dish with foil and place into the oven and bake at 350°F or 177°C 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.