Preheat the oven to 350°F (175°C).
Place the peanut butter cookies in a food processor and pulse until they form fine crumbs. Alternatively, place cookies in a sealed plastic bag and crush with a rolling pin until finely ground.
In a medium bowl, combine the crushed peanut butter cookies, melted unsalted butter, and granulated sugar. Stir until the mixture is evenly moistened and holds together when pressed.
Press the mixture firmly and evenly into the bottom and up the sides of a 9-inch pie pan or tart pan to form the crust.
Bake the crust in the preheated oven for 8 to 10 minutes, or until the edges are lightly golden and set.
Remove the crust from the oven and allow it to cool completely before filling.