|Source: Marcia Baum (2003)|
|Prep time: 4 hours|
Combine peanut butter and butter in bowl and microwave until soft. Stir in graham cracker crumbs and powdered sugar. Mix well. Pat into bottom of a 9 x 13-inch pan. Melt chocolate chips over low heat. Stir in cooking oil. Pour over crust and refrigerate for several hours. Cut into bars.