In a large bowl, stir together butter, graham cracker crumbs, powdered sugar and 1 cup peanut butter. Spread evenly in a 13x9 pan. Set aside.
In a microwave safe bowl, melt the chocolate chips and remaining 1/4 cup peanut butter in 30 second increments until smooth. Spread over the peanut butter layer. Refrigerate for 2 hours or overnight before cutting and serving.
