Preheat oven to 400°.
Pierce clean baked potatoes with a fork and bake at 400° for 1 hour and 10 minutes.
Cool, peel, and mash the potatoes.
Put flour in a large dutch oven and whisk in milk over medium heat.
Once the mixture begins to bubble, add the potatoes, half the cheese, salt, and pepper. Stir until well blended.
Reduce heat to low and add sour cream, heating for 10 minutes. Do not boil.
Serve in soup bowls with the remainder of the cheese and a slice of bacon crumbled on top.