Ganache is a chocolate preparation that is used as a glaze, icing, sauce, or filling for pastries. It is made by heating equal parts by weight of cream and chopped chocolate, warming the cream first, then pouring it over the chocolate. The mixture is then typically left to rest for a short period before it is stirred or blended until smooth, with liqueurs or extracts added if desired. Ganache can be used as a base for truffles or other candies, a frosting for cakes or filling for cake layers, or as a pourable glaze atop cakes or pastries. It can also be whipped to increase volume and spread as icing to cover a cake, and it becomes thicker as it cools. Ganache is very versatile and can be used in a multitude of desserts. The best chocolate for ganache is a pure chocolate baking bar, such as Bakers or Ghirardelli brands, and it is typically made with semi-sweet chocolate. Ganache can be stored in the refrigerator for up to 5 days and can be frozen for up to 3 months.