I generally bake Victoria sponge cake with 6 oz flour. Now to make a chocolate sponge cake do I substitute 2 oz of flour with cocoa powder or do I keep the 6 oz flour and add additional 2 oz cocoa powder.
I have seen some recipes that mention the former and some recipes mention the latter of what I mentioned above. Which of these 2 methods is the best way to prepare a chocolate sponge cake.