Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper.
In a large bowl, mix shredded chicken, cheddar cheese, mayonnaise, green onions, garlic powder, and black pepper until well combined.
Unroll crescent dough and separate into 8 triangles.
Spoon 2–3 tablespoons of chicken mixture onto the wide end of each triangle.
Roll each crescent from the wide end to the point, tucking edges slightly to seal the filling.
Place rolls on the baking sheet and sprinkle with Parmesan cheese.
Bake for 12–15 minutes or until golden brown.
Remove from oven and top with fresh parsley if desired. Cool for 2–3 minutes before serving.