Melt, by standing over hot water, three ounces of unsweetened chocolate; add a pound of sifted powdered sugar and mix thoroughly; work to a stiff yet pliable paste with the unbeaten whites of three eggs (or less), adding vanilla to flavor.
If the paste seems too soft, add more sugar.
Break off in small pieces and roll out about one fourth of an inch thick, sprinkling the board and paste with granulated sugar instead of flour.
Cut with a tiny heart shaped cake cutter (any other small cake cutter will do), and place on pans oiled just enough to prevent sticking.
Bake in a very moderate oven.
When done, they will feel firm to the touch, a solid crust having formed over the top.
They should be very light, and will loosen easily from the pan after being allowed to stand a moment to cool.
The success of these cakes depends upon the oven, which should not be as cool as for meringue, nor quite so hot as for sponge cakes.
If properly made, they are very excellent and but little labor.
Use the yolks for chocolate whips.