01 - Line an 8x8-inch a baking pan with parchment paper, ensuring there is overhang for easy removal convenience.
02 - In a substantial mixing bowl, combine 1 cup of creamy peanut butter, the melted unsalted butter, graham cracker crumbs, and powdered sugar. Stir until a homogenous mixture is achieved.
03 - Press the peanut butter mixture uniformly into the prepared pan. Utilize a spatula or your hands to craft a smooth and compact foundational layer.
04 - In a microwave-safe receptacle, meld the semi-sweet chocolate chips with 1/4 cup of creamy peanut butter. Microwave in 30-second increments, agitating between each, until the chocolate is fluid and smooth, typically requiring 1 to 2 minutes.
05 - Decant the liquefied chocolate mixture atop the peanut butter foundation. Spread evenly using a spatula to ensure complete coverage.
06 - Refrigerate the confection for a minimum of 40 minutes, or until the chocolate topping has solidified.
07 - Extract the set confection from the pan by gently pulling on the parchment overhang. Employ a sharp knife to divide into 16 individual bars. Serve chilled or at ambient temperature.