Cook the chocolate or cocoa in the water until a smooth paste is formed, stirring constantly while cooking. Cool, and add the baking soda.
Beat the egg yolks and whites separately. Mix as plain cake, adding the chocolate mixture after the egg yolks have been mixed with the sugar. Use the less quantity of salt if butter is used for the fat.
Bake in layers at 375 degrees F., placing Chocolate Filling between the layers and Boiled Frosting on the top layer.
Sour milk may be substituted for the sweet milk. When this is done, increase the baking soda to 1/2 teaspoonful and decrease the baking powder to 2 teaspoonfuls.
Baking soda is used with chocolate to neutralize a small quantity of acid (tartaric) contained in it. Its use with chocolate will also darken the cake.
CHOCOLATE FILLING
1/2 cupful sugar 1/3 cupful flour 1 cupful milk 1 ounce chocolate 3 tablespoonfuls water 1/4 teaspoonful salt 1 egg yolk 1 teaspoonful vanilla
Mix all ingredients except the egg yolk and flavoring in the same manner as Chocolate Corn-starch Pudding. When sufficiently cooked, add the egg yolk as directed for Butterscotch Tapioca. Continue cooking until the egg is coagulated. Remove from the fire, cool, add vanilla.
3 tablespoonfuls of cocoa may be substituted for the chocolate. When this substitution is made, mix the cocoa with the flour and sugar and omit the water.
The egg yolk may be omitted. When this is done add 1/2 tablespoonful of corn-starch to the flour and sugar mixture.