Preheat oven to 350°F. Line a 9×13-inch pan with foil and lightly coat with cooking spray.
Slice the rolls horizontally as one slab. Set the bottoms in the pan, cut side up.
Spread mayonnaise over the cut sides. Layer pickle slices on the bottoms, if using.
Shingle the turkey evenly over the bottoms, then top with the Swiss cheese. Cap with the roll tops.
Whisk melted butter, Dijon, Worcestershire, poppy seeds, onion powder, garlic powder, honey, salt, and pepper until smooth.
Brush the butter mixture over the roll tops, letting some drip down the sides. Cover the pan tightly with foil.
Bake covered for 12 minutes. Uncover and bake 6 minutes more, until the cheese melts and tops are lightly crisp.
Rest 5 minutes. Sprinkle with parsley, slice into individual sliders, and serve warm.