Ganache is normally made by heating heavy cream, then pouring it over chopped, dark chocolate. The mixture is stirred or blended until smooth, and can be enhanced with liqueurs or extracts. Depending on the kind of chocolate used, cream should be adjusted to reach desired consistency.
Ganache can also be used in filled chocolates, chocolate truffles, and other desserts. The portions of chocolate to cream vary depending on the intended usage of the ganache. Typically, a ganache is equal parts chocolate and cream; this is used for filling cakes. For a chocolate truffle base, twice as much chocolate as cream is used. For making a glaze, one should use three times as much chocolate as cream. Ganache can also be allowed to cool and whipped to increased volume and then spread to cover a cake.
Ganache is said to originate from a culinary accident, whereby a chocolatier's apprentice spilled cream in the chocolate he was melting. The chef called the apprentice 'Ganache', a word meaning, figuratively, 'fool'. The result was delicious, and the name stuck.