Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.

In a mixing bowl, combine the shredded chicken, barbecue sauce, garlic powder, salt, and pepper. Mix well to ensure the chicken is fully coated.

On a lightly floured surface, roll out each sheet of puff pastry to smoothen out creases. If needed, gently stretch it to make it slightly larger.

Evenly spread the chicken mixture over each puff pastry sheet, leaving a small border around the edges. Sprinkle the mozzarella and cheddar cheese evenly on top of the chicken mixture. Optionally, add chopped green onions for an extra layer of flavor.

Carefully roll each puff pastry sheet into a tight log, starting from one of the longer sides. Seal the edges with a bit of water to secure the roll. Slice the rolls into 1-inch (2.5 cm) pieces using a sharp knife.

Place the pinwheels on the prepared baking sheet, leaving some space between each. In a small bowl, beat the egg with a splash of water to create an egg wash. Brush this over the top of each pinwheel for a golden finish.

Bake in the preheated oven for 18-22 minutes or until the pinwheels are puffed and golden brown.

Remove from the oven and allow to cool slightly. Garnish with chopped parsley and serve warm.