light corn syrup
In small mixer bowl, beat together ½ cup peanut butter, butter, corn syrup and vanilla.
Stir in icing sugar until well blended.
Melt chocolate chips in measuring cup in the microwave or in a small pot on the stove and stir in ¼ cup peanut butter.
Gently stir this mixture slightly back into the peanut butter for a marble effect.
Pour into a small pie plate or pan and refrigerate until set.
Keep in refrigerator.
Cut into squares.