Make the peanut shortbread:
Line a straight-sided 13x9-inch metal baking pan with foil, letting the ends create an overhanging edge for easy removal.
In a medium bowl, stir together the butter, sugar, and salt. Stir in the flour and peanuts to make a stiff dough. Press the mixture evenly into the bottom of the prepared pan. Prick the dough all over with a fork. Refrigerate the pan for 30 minutes (or freeze for 5 to 7 minutes), until the dough is firm.
Meanwhile, position a rack near the center of the oven and heat the oven to 325°F.
Bake the dough for 20 minutes, then decrease the oven temperature to 300°F and bake until the crust is golden-brown all over and completely set, 20 to 25 more minutes. Let the crust cool completely before topping.
Make the peanut butter filling:
Put the peanut butter and butter in the bowl of a stand mixer fitted with the paddle attachment and beat on medium speed until smooth, about 1 minute. Add about half of the confectioners’ sugar to the mixer along with the vanilla extract and 1 Tbs. hot water. Beat on low speed until combined, then on medium speed until smooth and fluffy, about 1 more minute. Beat in the remaining sugar and mix, about 1 more minute, until the mixture is smooth and thick, like frosting. If the filling seems too stiff, add another 1 Tbs. hot water and beat for another minute.
With a knife or metal offset spatula, spread the filling over the fully cooled crust. The filling may not spread smoothly and evenly, but don’t worry; the ganache will cover it.
Macke the ganache:
Put the chocolate in a small heat proof bowl. In a small saucepan, bring the heavy cream to a boil. Remove from the heat and pour over the chocolate. Let sit for 3 minutes. Stir gently with a rubber spatula until combined and smooth.
Spread the ganache over the peanut-butter filling with a metal offset spatula to coat evenly. Let the bars sit at least 3 hours to allow the ganache to set before cutting (or refrigerate for 1 hour).
Carefully lift the bars from the pan using the foil sides and transfer them to a cutting board. Separate the foil from the bars by sliding a spatula between them. Cut the bars into 1-1/2-inch squares.
Make Ahead Tips
The bars will keep at room temperature for 1 week.
nutrition information (per serving):
per bar, Calories
11, Fat Calories
100, Saturated Fat
3, Monounsaturated Fat
13, Polyunsaturated Fat
Photo: Scott Phillips