Preheat oven to 350F. Line a 9x13-inch pan with aluminum foil and lightly spray with cooking spray.

Slice the Hawaiian rolls in half horizontally, keeping the rolls connected to create a slab of tops and bottoms.

Place the bottom slab of rolls in the prepared pan.

Layer half of the ham evenly over the rolls.

Layer Swiss cheese over the ham.

Add the remaining ham over the cheese.

Place the top slab of rolls over the assembled layers.

Melt butter in a microwave-safe bowl, about 1 minute on high.

Stir in Dijon mustard, poppy seeds, minced onion, Worcestershire sauce, salt, and pepper.

Slowly pour the butter mixture over the rolls, spreading with a spatula to distribute evenly.

Cover with foil and let sit at room temperature for 5 to 10 minutes.

Bake covered for 20 minutes, then remove foil and bake for an additional 5 minutes until hot and bubbly.

Slice into individual sliders and serve warm.