1 c. King Arthur Pasta Flour
4 egg yolks (one whole egg may be substituted for the yolks if a less rich noodle is desired)
1-1/2 T. water or milk
Combine all ingredients in a food processor and pulse a few times until blended. Form a ball with the dough. You can then knead by hand or pass the dough through a pasta machine. If kneading by hand, knead for 10 to 15 minutes until it is no longer elastic (when you poke it, the indent remains for more than a couple of seconds).
To knead by machine, cut the dough into 3 pieces. Crank each piece through the pasta machine at the widest setting. Fold it and pass it through again at the same setting until it feels smooth and silky (10 to 15 times), dusting as needed to keep it from sticking. Repeat for each piece of dough.
Put the dough in a plastic bag and let it rest for an hour and a half in the refrigerator (do not skip this step or the dough will be tough).
Pass the dough through the pasta machine first at the widest setting, then reducing one notch until the desired thickness is reached. Cut into noodles. Let rest 15 minutes, then cook in boiling water for 3 minutes.