Stir the bread crumbs and milk together in a medium-size mixing bowl. Let stand for 3 minutes so the crumbs absorb the milk.
Mix in the ricotta, egg yolks and whites, salt, and pepper, whisking to blend everything well.
Stir in the flour and baking powder until well blended.
Bring the stock or water to a simmer in a large pot.
Shape about 1 tbsp of the dumpling dough on a tbsp and drop into the simmering liquid. Repeat until all the dough is used. Cook for about 8 minutes, until the dumplings are cooked through. You may need to cut one in half to check.