In a 4- to 6-quart slow cooker, mix together the frozen hash brown potatoes (no need to thaw), cream of chicken soup, chicken stock, ranch seasoning, onion powder, garlic powder, pepper, and about ¾ cup of the crumbled bacon.
Cover the slow cooker and set it to LOW. Cook for 5–6 hours, or until the potatoes are tender.
Stir in the cream cheese, shredded cheddar cheese, and heavy cream. Cover again, increase the heat to HIGH, and cook for an additional 30–45 minutes, until the cheeses are fully melted and the soup has thickened slightly. If small bits of cream cheese remain, whisk the soup to incorporate them into the base.
For the best texture, turn the slow cooker to WARM and let the soup rest for 10–15 minutes. It will thicken as it stands. If you prefer your soup to be even thicker, use a potato masher to mash some of the potatoes, leaving some chunks intact for texture.
Taste the soup and adjust the seasoning with salt and pepper. Ladle the soup into bowls and top with the reserved crumbled bacon, shredded cheddar cheese, and snipped chives or sliced scallions. For an extra touch, add a small dollop of sour cream to each bowl, just like a loaded baked potato.
