For the peanut shortbread crust:
7 ounces (14 tablespoons) unsalted butter, melted and cooled to just warm
1/2 cup granulated sugar
1/2 teaspoon table salt
9 1/2 ounces (2 cups plus 2 tablespoons) 
unbleached all-purpose flour
1/2 cup unsalted peanuts, finely chopped

For the peanut butter filling:
1 cup creamy peanut butter (not natural but an emulsified variety such as Jif)
3 ounces (6 tablespoons) unsalted butter, at room temperature
6 ounces (1 1/2 cups) confectioners’ sugar
1 teaspoon pure vanilla extract

For the ganache:
5 ounces good-quality bittersweet chocolate, such as Lindt Excellence, chopped (about 1 heaping cup)
1/2 cup plus 2 tablespoons heavy cream