Preheat the oven to 350°F
Slice Hawaiian rolls in half horizontally without separating the rolls
Place the bottom half of the rolls in a baking dish
Layer ham evenly over the bottom half
Layer cheese slices over the ham
Place the top half of the rolls over the cheese
Melt butter in a saucepan or microwave
Stir in Dijon mustard
Stir in Worcestershire sauce
Stir in garlic powder
Stir in onion powder
Stir in poppy seeds if desired
Brush or pour the butter mixture evenly over the tops of the rolls
Cover the dish with foil
Bake for 15 to 20 minutes
Remove the foil
Bake for 5 more minutes until the tops are golden and the cheese is melted
Slice and serve warm