In a large bowl, combine the mashed potatoes, cheese, egg, 3 tablespoons of flour, Craisins®, and salt and pepper; mix until combined. Should be a dough-like consistency, add flour as needed. Empty onto floured surface and roll to ½ inch thick slab. Cut round slices using pastry cutter; re-roll and cut any leftover dough. Place remaining flour in a shallow dish and dredge each pancake lightly in flour. Heat half the oil in a large pan over medium-heat, adding more when needed during frying. Once the oil is hot, fry fritters in batches until golden brown and crispy on each side, about 3 minutes per side. Do not crowd the pan Remove cooked fritters to a paper towel-lined plate or wire rack and sprinkle with salt. Garnish with fresh parsley, top with sour cream (optional) or enjoy with your favorite sauce. Air Fryer Alternative: instead of pan-frying fritters, place cut rounds into an air fryer and “fry” for 15 minutes at 400F, flipping them halfway through.