The necessary material for making chocolate cakes is pure cocoa powder without other ingredients. Generally, the beverages with sugar and milk powder are sold in supermarkets, which are not suitable. When making chocolate cakes, usually add 30 grams of cocoa powder to a Usually a two-pound cake, because cocoa powder is acidic, when used in large quantities, the cake will have a sour taste, so a small amount of baking soda can be used as a neutralizer to neutralize the acidity and darken the color of the chocolate cake.