The key to baking is ratios; if you know the ratio behind a type of recipe, say for cake or cookies, it is very easy to make variations on that recipe, or even create your own. In baking, ratios refer most typically to the weights of ingredients. For example, saying that dark chocolate ganache has 1:1 part ratio of cream to chocolate means that ganache is made from equal parts (by weight) of cream and dark chocolate. White chocolate ganache on the other hand has a 1:2 part ratio meaning that you would need double the weight of white chocolate to cream.