adapted from Dorie Greenspan
1 cup flour
1/4 cup sugar
2 Tbsp confectioner's sugar
1/4 tsp salt
1 stick (8 Tbsp) butter, cut into pieces and cold
1 large egg yolk, lightly beaten (reserve white)
1/3 cup sugar
3 Tbsp water
1 1/2 cups dry roasted (what I used) or salted peanuts
1 can (1.5 cups) store bought dulce de leche
7 ounces bittersweet chocolate, coarsely chopped
1/2 stick (4 Tbsp) butter, cut into 8 pieces, and at room temperature
Preheat the oven to 350˚; butter an 8" square pan.
Combine flour, sugar, confectioner's sugar, and salt together and whisk. Add cold, diced butter and use your fingers, 2 knives, or a pastry blender to mix it in until you have a pebbly mixture (like pie crust!) Add egg yolk and blend until you get clumps and curds. If needed, add a little egg white to moisten it further (I needed, but I don't think I would have if I would have followed the food processor tip below.)
Gently press the dough into the buttered pan, making it as even as possible. Prick it all over with a fork, then send it to the oven, baking for 15-20 minutes, or until it just starts to color. Cool on a rack until room temperature before adding the rest.
For the filling, lay a sheet of parchment on your counter and grab a long-handled wooden spoon. Combine water and sugar in a small, heavy-bottomed saucepan and cook over medium high heat, stirring until the sugar dissolves. Once the sugar is dissolved, stop stirring, but continue heating until the caramel just starts to color. Add the peanuts and stir. Likely your caramel will cool and turn white on the peanuts, but keep stirring, and it'll re-caramelize. Keep cooking and stirring until the peanuts are covered with a dark, golden, amber caramel; this might take less time than you expect—it did for me. Immediately dump the nuts onto your prepared parchment and spread them with the spoon as thin as you can. Cool. When they are cool, separate the nuts into individual pieces as best you can. Take half of them and chop them for your topping and set aside. Take the remaining larger pieces and combine them with the dulce de leche and mix well; spread this evenly over the cooled shortbread.
Melt chocolate in a double boiler or in the microwave. Remove from heat and gently stir in butter until fully blended. Pour chocolate over the dulce de leche and smooth it with an offset spatula. Sprinkle with chopped peanuts and slide it into the refrigerator to set (20-30 minutes.)
Alternately, you can make the shortbread in a food processor by tossing in the flour, sugars, and salt, then pulsing in the butter, and finally pulsing the yolk into the crumbs, stopping before it comes together entirely.
These are also amazing thoroughly chilled (3 hours+) but the shortbread tend to crumble, so I set the chocolate, cut them and put them on a plate, then put them back into the refrigerator to get firm and chewy.
I found that I used fewer dishes if I washed while things were cooling. My caramel saucepan=lower half of my double boiler. 2 steps, 1 pan, fewer dishes. When you're on a baking binge like this, you have to be mindful of the dishes.