Place the bottom halves of the rolls on a baking sheet.
Layer 6 slices of ham on top of the bottom roll halves.
Place 3 slices of Swiss cheese over the ham.
Layer the remaining 6 slices of ham on top of the cheese.
Place the top halves of the rolls over the ham.
In a small bowl, whisk together the melted butter, Dijon mustard, Worcestershire sauce, garlic powder, salt, and pepper.
Pour the butter mixture evenly over the tops of the sliders.
Cover the baking sheet tightly with aluminum foil.
Bake for 15 minutes.
Remove the foil and bake for another 5-10 minutes, or until the tops are golden brown and the cheese is melted.
Let the sliders rest for a few minutes before slicing and serving.
Notes
For make-ahead convenience, assemble the sliders up to 24 hours in advance. Cover tightly and refrigerate. Bake as directed, adding a few extra minutes to the covered baking time.
You can substitute cheddar cheese or provolone for Swiss cheese if desired.
Add a sprinkle of poppy seeds to the butter mixture for extra flavor.