I have an uncle who is the quintessential chocoholic. There is no chocolate treat too chocolately for him. Each Christmas I make him a batch of fudge and he savors it for weeks. This year, however, I had these Salted Caramel Chocolate Shortbread Bars on my mind and wanted a reason to make them (like I need a reason). My uncle was most appreciative. They are very chocolatey and very rich. I packed my uncle a full tin and had some left to put out for dessert on New Year's Eve. The recipe makes a lot because you really need to cut them small.
I halved the ingredients for the caramel because I didn't want the chocolate to be over-powered. I think, however, the chocolate can hold its own (the recipe is listed below as Annie originally listed it). I spoke with a friend about her experience with this recipe. She said she never got her caramel to darken because she was afraid the caramel would get too chewy (she didn't have a candy thermometer). I put my candy thermometer in the pan to make certain the caramel didn't reach too high a temperature and I'll tell you it took almost 30 minutes to achieve the color I did. Mine still was not as dark as Annie's.
Salted Caramel Chocolate Shortbread Bars
For the shortbread layer:
2 cups all-purpose flour
2 tsp. baking powder
¼ tsp. salt
1 cup (2 sticks) unsalted butter, at room temperature
½ cup sugar
For the caramel layer:
1 cup (2 sticks) unsalted butter, cut into pieces
1 cup sugar
4 tbsp. light corn syrup
2 (14 oz.) cans sweetened condensed milk
For the chocolate layer::
8 oz. semisweet or bittersweet chocolate, finely chopped
1 tsp. light corn syrup
½ cup (1 stick) unsalted butter, cut into pieces Fleur de sel or sea salt, for sprinkling
To make the shortbread layer, preheat the oven to 325° F. Line a 9 x 13-inch baking pan with parchment paper. In a small bowl combine the flour, baking powder and salt. Stir with a fork to blend, and set aside. In the bowl of an electric mixer, beat the butter and sugar on medium speed until well blended, about 1-2 minutes. With the mixer on low speed blend in the dry ingredients just until incorporated. Transfer the dough to the prepared baking pan and press in an even layer over the bottom of the pan. Bake 15-18 minutes or until golden. (If the crust puffs up a bit while baking, just gently press it down while it is cooling.) Transfer the pan to a wire rack and let cool completely.
To make the caramel layer, combine the butter, sugar, corn syrup and condensed milk in a medium saucepan over medium heat. Heat, stirring occasionally, until the butter is melted. Increase the heat to medium-high and bring to a boil. Reduce the heat to maintain a simmer, stirring constantly. Continue simmering and stirring until the mixture turns an amber color and thickens slightly. Pour the mixture over the shortbread layer, smooth the top, and allow to cool completely and set. (I chilled at this stage to ensure that the caramel layer would not melt when the warm chocolate was added.)
To make the chocolate glaze, combine the chocolate, corn syrup, and butter in a heatproof bowl set over a pan of simmering water. Heat, stirring occasionally, until the chocolate is completely melted and the mixture is smooth. Pour evenly over the caramel layer and use an offset spatula to smooth the top. Allow to cool for a minute or two and then sprinkle with salt (I had to chill them for more than a few minutes before the chocolate set enough for the salt not to dissolve on contact). Chill, covered, until ready to slice and serve.