01 -
Preheat oven to 350°F. Lightly grease an 11-inch rectangular baking dish with nonstick spray.
02 -
With a large serrated knife, slice the rolls in half horizontally so you have one slab of tops and one slab of bottoms, keeping them connected.
03 -
Spread Dijon mustard evenly over the cut sides of both slabs.
04 -
On the bottom slab, place half of the sliced Swiss cheese, then layer with ham, turkey, and finish with the remaining cheese slices.
05 -
Carefully replace the top half of the rolls and set the assembled sliders back into the prepared baking dish.
06 -
In a small bowl, whisk the melted butter with the egg until fully combined. Brush this mixture evenly over the tops of the rolls.
07 -
Tent the baking dish loosely with foil, ensuring the foil does not touch the bread. Bake for 15 minutes.
08 -
Remove the foil and continue baking for another 10 minutes, or until the tops are golden brown.
09 -
Let cool slightly. Separate the sliders with a sharp knife. Dust with powdered sugar and serve hot, ideally with berry preserves on the side.