Preheat the oven to 350°F (175°C). Lightly grease a 9x13-inch baking dish.
Slice the rolls in half horizontally without separating them individually.
Place the bottom halves of the rolls in the prepared baking dish.
Layer the ham evenly over the rolls, followed by the Swiss cheese slices.
Place the top halves of the rolls back on.
In a small bowl, whisk together the melted butter, Dijon mustard, Worcestershire sauce, garlic powder, onion powder, poppy seeds, salt, and pepper.
Brush the butter mixture evenly over the tops of the sandwiches.
Cover the dish with aluminum foil and bake for 15 minutes.
Remove the foil and bake for another 5-10 minutes, until the tops are golden brown and crispy.
Serve warm and enjoy!