Eggs.
Eggs have tried to be replaced by more substitutes than any other ingredient used in cake making. The first thing to consider in an egg substitute is, does it beat up well, as for sponge cakes? You cannot beat up or use many substitutes for sponge cake; but you can use them for anything else. However, half the quantity of eggs regularly used will often make a better cake than you can buy, using egg substitutes.
Eggs are often wasted, more being used than necessary, and where they are of no benefit. It is poor policy to buy cheap eggs, as they are dear compared to good ones, considering the little difference in price, sometimes being only two or three cents a dozen, which makes them dearer in the end than good eggs.
Eggs known as “Spots” among bakers are not only entirely worthless but often spoil a cake.