

If the chocolate gets too cool, just gently rewarm it to the appropriate temperature.You can tell that it has gotten too cool by its appearance, which will become matte and thicker when you stir it.Tempered chocolate will quickly solidify as it cools, so you'll need to move as quickly as possible.

Then, stir the chocolate until smooth, while monitoring the temperature using a candy thermometer.Let the chocolate sit in the bowl over the saucepan of hot water until in begins to melt around the edges.Add the chocolate to a heat-proof bowl (or the top portion of a double boiler if you have one), and place the bowl on top of the saucepan.Place a medium saucepan filled about half way with water over medium-low heat on your stove.If it has cooled too much that it is no longer pourable, then slightly rewarm over low heat. It should still be pourable for assembly. Let cool slightly while you prepare the chocolate.Remove from heat and stir in the vanilla extract.Carefully the cream mixture (mixture will bubble up) and simmer, stirring frequently, until caramel registers 248☏ on thermometer, 10 to 15 minutes.* (see note below regarding altitude).Boil, without stirring but gently swirling pan, until mixture is a light golden caramel and sugar is dissolved.Combine sugar, corn syrup, and water in a 4-quart heavy saucepan.Bring cream, butter, and salt to a boil in a small saucepan, then remove from heat and set aside.(Related: Kitchen Tip: Lining Pans with Parchment) Line bottom and sides of an 9-inch square baking pan with parchment paper.
