peanut butter chocolate bars (no bake)

2 c. confectioners' sugar
2 c. graham cracker crumbs
1 c. smooth peanut butter ( I use chunky peanut butter, just a personal preference)
1/2 c. plus 2 tbsp. butter, melted
2 c. (12 oz.) milk chocolate or semi-sweet chocolate chips, melted

Have ready 9x13 inch baking pan. Mix confectioners' sugar, graham crackers, peanut butter and butter in medium bowl until well blended. Scrape into ungreased baking pan and press into even layer. Spread melted chocolate over top. Refrigerate at least 2 hours until chocolate is firm. Let stand 10-20 minutes at room temperature before cutting into bars.