Preheat oven to 400° (F)
Using a fork, poke holes in potatoes and bake for 1 hour, or until tender. Remove from oven and reduce heat to 350°.
When cool enough to handle, cut potatoes in half lengthwise and spoon out the insides into a large bowl.Place skins on a large sheet pan.
In the potato bowl, add the sour cream, melted butter, cream cheese, green onions, salt, pepper, milk, and seasoning packet. Mash and stir until smooth. Fold in half of the cheese.
Spoon the mixture back into the potato skins. Top with remaining cheese and bake for 20 minutes.