Combine the chicken stock, potatoes, carrots, and unsalted butter in a large dutch oven or pot. Bring the whole thing to a boil and cook until the potatoes and carrots are tender when poked with a fork, about 10-15 minutes. Add in the diced pickles and continue to boil.
Meanwhile, in a bowl stir together the sour cream, all-purpose flour, and water to make a paste which will thicken the soup. Add the mixture, about 1/4 cup at a time to the boiling hot broth while whisking constantly.
Once all the mixture is added in, turn the stove to medium heat and add in the dill pickle juice, Old Bay, marjoram, salt, black pepper, and cayenne powder and cook an additional five minutes.
Remove from the heat and top with fresh sliced pickles, chopped dill and a dollop of sour cream.