Boil the potatoes in their skins in lightly salted water. Cook for about 15 minutes, or until a paring knife easily pierces the outer part and the knife meets resistance about ½ inch into the potato. Drain, cool, and refrigerate.

Peel the potatoes and shred on a grater. Pour half of the butter into a large 15-inch skillet. Heat the butter over moderately high heat and add the shredded potatoes. Sprinkle liberally with salt and pepper. Push the stray shreds in from the rim of the pan and pat the top into a large pancake. Reduce the heat and cook, shaking and rotating the pan to loosen the potatoes. Drizzle a few tablespoons of butter around the inner rim of the pan. Continue to cook for 15 minutes.

Invert the skillet and slide the potatoes out of the pan onto a large plate. Slide the pancake into the skillet, cooked side up, and drizzle the remaining butter around the inner rim. Drizzle the syrup in the same manner. Continue to cook until golden. Use a rubber spatula and lift from the edge when checking for doneness. Sprinkle with the parsley and serve.