The reason natural cocoa powder can't be substituted with Dutch process cocoa powder is because they have different levels of acidity. Each type works differently with the rest of the ingredients in the recipe. I have formulated this recipe to work with natural cocoa powder, so this is the type of cocoa you will need. If you only have Dutch process cocoa powder on hand, I suggest searching for a Dutch process cupcake recipe so that you can guarantee your cupcakes will turn out properly.