Ganache is normally made by heating cream, then pouring it over chopped chocolate of any kind. The mixture is stirred or blended until smooth, with liqueurs or extracts added if desired.
Depending on the kind of chocolate used, for what purpose the ganache is intended, and the temperature at which it will be served, the ratio of chocolate to cream is varied to obtain the desired consistency. Typically, two parts chocolate to one part cream are used for filling cakes or as a base for making chocolate truffles, while one to one is commonly used as a glaze. Cooled ganache can be whipped to increase volume and spread to cover a cake. However, if left to cool too much it can become too thick and unspreadable.