Preheat oven to 400°F (200°C).
Poke potatoes with a fork, place directly on oven rack, and bake for 50-60 minutes until tender.
Let cool, then peel and dice into small cubes. (Shortcut: Microwave for 8-10 minutes, flipping halfway through.)
In a large pot or Dutch oven, cook the bacon over medium heat until crispy (7-8 minutes).
Remove bacon, drain on paper towels, and set aside. Reserve some bacon grease in the pot for flavor.
In the same pot, melt 3 tablespoons butter over medium heat.
Add chopped onion and cook until soft (5 minutes).
Stir in minced garlic and cook for 30 seconds until fragrant.
Sprinkle 3 tablespoons flour over the onions, stirring constantly for 1-2 minutes to create a smooth base.
Slowly whisk in 4 cups chicken broth, stirring to prevent lumps.
Pour in 2 cups milk and 1 cup heavy cream, then bring to a gentle simmer for 5 minutes to thicken.
Stir in diced baked potatoes and let cook for 10 minutes, stirring occasionally.
Mash some of the potatoes with the back of a spoon for a thicker texture.
Reduce heat to low and stir in 1½ cups cheddar cheese until fully melted.
Turn off heat and stir in ½ cup sour cream for a creamy, tangy finish.
Add salt, black pepper, and smoked paprika (if using) to taste.
Ladle into bowls and top with crispy bacon, extra cheese, green onions, and a dollop of sour cream.
Serve hot with crusty bread or garlic toast for the best experience.