Preheat oven to 350 F. Line a 9X9 inch or 9X3 inch pan with aluminum foil, spray with cooking spray; set aside.
Using a large serrated knife, slice the rolls in half so you have a slabe of tops and a slab of bottoms; don't pull the rolls apart and slice individually because you want to keep them connected. Place the bottom slab of rolls in prepared pan.
Evenly layer about half of the ham over the rolls.
Evenly layer the cheese.
Evenly layer the remaining ham.
Add the top slab of rolls; set aside.
To a medium microwave safe bowl, add the butter and heat on high power to melt, about 1 minute.
Add the mustard, poppy seeds, onion, Worcestershire sauce, salt, pepper, and whisk to combine.
Evenly and slowly pour the butter mixture over the rolls. Use a spatula to spread the mixture over the tops. Some of the mixture will pool at the base of the rolls.
Cover with aluminum foil and allow to stand at room temp for about 5 to 10 minutes.
Bake covered for 20 minutes or until cheese has melted.
Uncover and cook for about 3 to 5 minutes, or until as done as desired.