Cowardly chop the potatoes (leaving the skin on) and set aside.

Cook the bacon until crisp in a large nonstick saucepan set over medium heat; drain on paper towels and set aside. Pour off and discard all but 1 teaspoon of the drippings.

Add half the scallions and the garlic to the drippings in the saucepan and return to medium heat. Cook, stirring occasionally, until softened, about 3 minutes. Add the broth, salt, cayenne, and chopped potatoes, mashing the potatoes slightly with a wooden spoon to break then up a bit. Bring mixture to a boil. Reduce the heat and summer, uncovered, until heated through, 2-3 minutes. Stir in half-and-half and parsley; return to a simmer. Serve the soup sprinkled with the crumbled bacon and the remaining scallions.