Lightly butter a 9-inch square metal baking pan and line with parchment paper, leaving a 2-inch overhang on all sides. Butter parchment. In a food processor, pulse wafers until finely ground (you should have about 2 1/2 cups). Transfer to a large bowl; whisk in confectioners' sugar and salt. In a medium microwave-safe bowl, microwave butter and peanut butter in 30-second increments, stirring, until melted and smooth, about 1 1/2 minutes. Stir into wafer crumb mixture and let cool to room temperature, about 10 minutes.
Fold in nougat and wafer candy bars, then transfer to pan. With a small spatula, press mixture evenly into pan. Refrigerate until set, about 30 minutes. In clean microwave-safe bowl, microwave crisped-rice candy bars in 30-second increments until just melted. Pour over chilled mixture and, with spatula, spread evenly. Refrigerate until set, 20 minutes. Using parchment, lift confection from pan and cut into 27 bars.