Preheat your oven to 375°F (190°C). Grease a 9×13 inch baking dish with cooking spray or butter and set aside.

In a large mixing bowl, combine cream of chicken soup, sour cream, milk, garlic powder, and black pepper. Whisk until smooth and well blended. Stir in 2 cups of shredded cheddar cheese and the diced ham until evenly distributed.

Spread half of the frozen tater tots in an even layer on the bottom of the prepared baking dish. Pour the ham and cheese mixture over the tater tots, spreading it evenly. Arrange the remaining tater tots on top in a single layer.

Cover the baking dish with aluminum foil and bake for 30 minutes. Remove the foil, sprinkle the remaining 1 cup of cheddar cheese over the top, and continue baking uncovered for 15 minutes until the tater tots are golden brown and crispy.

Remove from oven and let the casserole rest for 5 minutes. Garnish with chopped fresh parsley and serve hot. Enjoy the gooey, cheesy goodness!