Boil the potatoes in plenty of hot water.
Mash them using a potato masher and, while still warm, mix in the flour, spinach powder, breadcrumbs, the egg, and finally the yeast. Stir until all ingredients are well combined.
Dust your work surface with flour and roll the dough into ropes about 2–3 cm in diameter. Cut into gnocchi pieces about 2–3 cm long.
Cook the gnocchi in salted boiling water until they float to the surface. Drain and serve with your favorite sauce.