Preheat the Oven – Adjust the oven rack to the middle position. Heat to 350°F (177°C). Line a rimmed baking sheet with parchment paper or foil and set aside.
Make the Butter Sauce - Heat the butter in the microwave in 15-second increments until melted. Stir in the Dijon mustard, honey, Worcestershire sauce, onion powder, and salt. Set aside.
Slice the Rolls – Use a serrated knife to cut the rolls in half lengthwise, keeping them intact once sliced.
Assemble the Sliders – Place the bottom half of the rolls cut-side up on the lined sheet pan. Layer 6 slices of Swiss cheese, overlapping to cover the bread. Evenly layer the ham on top. Brush the ham with about half of the butter sauce. Layer the remaining 4 slices of Swiss cheese on top. Place the top half of the rolls on the assembled sliders. Brush the remaining butter sauce over the tops. Sprinkle the seeds on top.
Bake the Sliders – Cover the sliders with foil. Bake for 15 minutes, then uncover. Bake until the cheese is melted and the tops are lightly brown, about 5 minutes.
To Serve – Transfer the sliders to a cutting board, then cut into individual sliders. Transfer to a platter and serve immediately while hot.
Notes
Heartier Sliders: Add 1 pound of ham to the sliders.
Everything Bagel Seasoning Substitute: Use poppy seeds or sesame seeds.
Storing:Cover and store in the refrigerator for up to two days.
Freezing:Wrap the assembled rolls in plastic and foil. Freeze for up to 3 months. Defrost in the refrigerator, brush with seasoned butter and bake according to recipe directions.
Reheating:Heat the sliders in the microwave on high setting in 15-second increments until the rolls are soft and the filling is warm.