This pie has a top-notch combination of textures and flavors: It boasts a silken peanut-butter filling, crisp chocolate-cookie crust, and crunchy peanut topping.
Preheat oven to 350 degrees. Place cookies in a food processor, and process until finely ground (you should have 1 3/4 cups); add butter, and pulse until moistened. Transfer crumb mixture to a 9-inch removable-bottom tart pan. Press firmly into the bottom and up the sides (use bottom of a dry measuring cup to help). Bake until fragrant and set, 15 to 20 minutes; let cool completely. Wipe food processor clean, and reserve.
Place 1/4 cup cold water in a small saucepan; sprinkle with gelatin. Set aside to soften, 5 to 10 minutes.
In food processor, combine sugar and peanut butter; process until smooth. Add cream; process until mixture is light and holds soft peaks, scraping down sides of bowl as necessary.
Heat softened gelatin over very low heat, stirring, just until dissolved. Add to peanut-butter mixture in food processor; blend to combine. Transfer filling to cooled crust, and smooth top. Sprinkle with peanuts, and chill until set, at least 2 hours and up to 3 days.
To create a firm crumb crust with an even thickness, use the bottom of a dry measuring cup and your fingers to press the crumbs out from the center of the pan and up the sides.