Melt chocolate chips and peanut butter in sauce pan, stir over low heat until melted and smooth. Spread in greased 9" by 13" baking pan. Refrigerate until set.
Melt butter, add sugar and milk and bring to a boil. Boil and stir for 5 minutes. Remove from heat and stir in peanut butter, vanilla, and marshmallow cream. Stir in peanuts and spread over Layer 1 and refrigerate until set.
Combine caramels with heavy cream and heat until melted and smooth. Spread over Layer 2, refrigerate until set.
Melt chocolate chips and peanut butter over low heat until melted and smooth. Pour over top and refrigerate overnight.