Heat oven to 350°F. Line a 9×13-inch pan with parchment or lightly grease.
Beat cream cheese with ranch seasoning until smooth. Fold in chicken, half the cheddar, bacon, and 1 tablespoon green onions.
Slice the rolls horizontally as one slab. Set the bottoms in the pan.
Spread the chicken mixture evenly over the bottoms. Sprinkle on remaining cheddar. Cap with the roll tops.
Stir melted butter with Worcestershire, garlic powder, onion powder, poppy seeds, salt, and pepper. Brush over the tops.
Cover pan with foil and bake 15 minutes. Uncover and bake 5–7 minutes more, until tops are golden and cheese melts.
Scatter remaining green onions. Let rest 5 minutes, then slice and serve warm.