Re-post from previous topic:
Things to think of:
1. that much cocoa is supplying structure as well as taste to the completed product. Adding flour as a substitute for cocoa is also adding more gluten .. cocoa has no gluten. Gluten gives elasticity and strength to baked goods. But cake should be soft and light - that means not adding more gluten. Too much causes a tough, dry cake.
2. cocoa in a baked product is very drying - more liquid is required to balance this tendency. Removing the cocoa will unbalance the moisture content
3. natural cocoa is acidic in nature: to balance this, there is usually an alkaline item in the recipe: bicarb soda, buttermilk, sour cream, yoghurt etc. The chemical reaction neutralizes but it also acts as a secondary leavener. Removing the cocoa, means that another item will have to be introduced to counter the alkaline ingredient
4. if there is no primary leavener, and you remove one of the catalsyts of the acid/alkali reaction, you will have to add some type of leavener or the item may not rise ..
Suggestion: look for another recipe ..