Mash potatoes while warm. Allow to cool. Add salt, flour and egg yolks. Add flour if needed. Turn onto floured surface and knead. Using small amounts of dough, roll into strands 1/4" thick round, cut into 3/4" lengths.
2
Boil 3 quarts water, drop gnocchi in a few at a time. When they floatboil 3 minutes more. Drain and serve with spaghetti sauce.