Preheat the oven to 400°F (200°C).
Scrub the russet potatoes clean and pat them dry.
Prick each potato several times with a fork and rub them with olive oil, then sprinkle with salt.
Place the potatoes directly on the oven rack and bake for 45 to 50 minutes, or until tender when pierced with a fork.
Remove the potatoes from the oven and let them cool slightly until they are safe to handle.
Reduce the oven temperature to 350°F (175°C).
Cut each potato in half lengthwise and carefully scoop out the flesh into a large mixing bowl, leaving about 1/4 inch of potato flesh in the skins to maintain structure.
Add the butter, sour cream, milk, garlic powder, onion powder, smoked paprika, salt, and black pepper to the potato flesh. Mash until smooth and creamy.
Stir in the shredded chicken, 1/2 cup cheddar cheese, 1/4 cup mozzarella cheese, chopped green onions, and crumbled bacon until well combined.
Spoon the potato and chicken mixture evenly back into the potato skins and place them in a greased 9×13 inch casserole dish.
Sprinkle the remaining 1/2 cup cheddar cheese and 1/4 cup mozzarella cheese evenly over the filled potato skins.
Bake the casserole at 350°F (175°C) for 20 minutes, or until the cheese is melted and bubbly.
Remove from the oven and garnish with chopped fresh parsley before serving.