Preheat the oven to 375°F (190°C). Line a baking tray with parchment paper.
In a bowl, mix shredded chicken, mayo, sriracha, garlic powder, onion powder, salt, pepper, and mozzarella. Set aside.
Slice the tops off the buns and carefully hollow out the centers without breaking the bottoms.
Spoon the spicy cheesy chicken mix into each bun. Press the tops back on.
Brush each bun with melted butter and sprinkle with parsley if you like.
Bake for 15 to 20 minutes until the tops are golden and the filling is hot and gooey.
Cool for a few minutes before serving—if you can wait that long!