Ingredients:
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
Instructions:
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 fleur de sel. Chill, covered, until ready to slice and
serve.