1. Preheat oven to 400°. Prick all potatoes with a fork, and bake on a jelly-roll pan 1 hour.
2. Cool potatoes 20 minutes. Peel and mash until smooth. Add cheese and next 4 ingredients, and stir until smooth. Fold in flour just until blended.
3. Divide dough into 4 equal portions; dust with flour. Roll each into a 3/4-inch-diameter rope on a well-floured surface. Cut into 1-inch pieces; place dumplings on a lightly floured baking sheet.
4. Cook dumplings, 10 to 12 at a time, in 3 qt. boiling water over medium-high heat, 3 minutes. Remove with a slotted spoon.