1. Have ready a 9-by-13 inch pan. In a medium saucepan over low heat, melt butter and peanut butter together, stirring until smooth and blended.
2. Remove pan from heat. Stir in graham cracker crumbs and confectioners' sugar. The mixture will be very stiff.
3. Press the peanut butter mixture into the 9-by-13 inch pan. Set aside.
4. Place chocolate chips in a microwave-safe bowl. Cook on high for 1 minute. Stir, and cook again on half power for 30 to 60 seconds, just until the chocolate is melted. Stir until smooth. Spread melted chocolate in an even layer over the peanut butter layer.
5. Let set at room temperature, about 1 1/2 to 2 hours. Cut into 36 squares and serve.
Source: Hannaford fresh Magazine, November - December 2011