Dark chocolate ganache is made of a 1 to 1 ratio of dark chocolate and warm heavy cream or heavy whipping cream. Use good quality baking bars or wafers that include a minimum of 50% cocoa content for this recipe (bittersweet or semi-sweet chocolate). Milk chocolate and white chocolate will not work with the 1 to 1 ratio as they have significantly less cocoa content and are much softer. Simply put, they require less cream.