Preheat the oven to 350°F (175°C).
Slice the sandwich rolls in half and place the bottom halves in a baking dish.
Layer each with 2 slices of ham and 1 slice of Swiss cheese.
Cover with the top halves of the rolls.
In a small bowl, mix the melted butter, Dijon mustard, garlic powder, onion powder, Worcestershire sauce, and poppy seeds.
Brush the butter mixture evenly over the tops of the sandwiches.
Cover the baking dish with foil and bake for 15 minutes.
Remove the foil and bake for another 5 minutes until golden brown.
Serve warm and enjoy!