Line with parchment paper or grease two 8" square pans or a 9 x 13" pan.
Combine peanut butter and marshmallow cream in a large bowl - at least 6 quart or larger. Helps to microwave the jars for a little while before trying to mix together.
In a 5 quart pan combine butter, milk and sugar. Heat on medium high, stirring constantly. It is very important to dissolve the sugar before moving on.
Once this mixture has melted add chocolate chips. Stir constantly until mixture reaches a rolling boil.
Turn heat down to medium-low and time for 6 minutes, stirring constantly.
Pour hot mixture into bowl with marshmallow cream and peanut butter. Work quickly to stir vigorously until combined.
Pour mixture into prepared pans. Store in a cool place until set.