Scrub the potatoes and bake at 400°F (205°C) for 50–70 minutes, until completely tender.
Cut the potatoes open lengthwise and let the steam escape for a few minutes.
While still warm, press the flesh through a potato ricer onto a clean counter or sheet pan. Let it sit 5–10 minutes.
Sprinkle with salt, egg, and flour. Start with less flour — you can always add more.
Gently fold together with your hands or a bench scraper until just combined. Don't knead.
Pinch off one piece and test it in gently boiling water. If it holds together and floats, the dough is ready.
Divide the dough, roll into ropes, and cut into 1-inch pieces. Roll over a fork for ridges if desired.
Boil in batches. When they float, cook 30–60 seconds more, then remove with a slotted spoon.
Finish in melted butter in a skillet, tossing until coated (browning lightly first if you prefer), then add your sauce of choice.
