• Butter bottom and sides of a 13x9 pan (or square pan if you want the bars thicker)
• In a medium bowl, stir together butter, peanut butter, graham cracker crumbs and powdered sugar until smooth and creamy.
• Press mixture into prepared pan.

Frosting:

• In a microwave safe bowl combine peanut butter, and chocolate chips and heat for 30 seconds. Stir and continue heating 10 seconds at a time until the chips are almost melted. Stir until completely smooth.
• Spread evenly over the peanut butter bars layer.

Chill

• Chill in refrigerator at least 2 hours or until firm.
• Remove from the refrigerator and cut into bars.
• Serve chilled.