To Make Base: Combine 1 cup milk chocolate chips, 1/4 cup butterscotch chips and 1/4 cup creamy peanut butter in a small saucepan. Cook, stirring constantly, over low heat until melted and smooth. Spread into the bottom of the prepared pan. Refrigerate until set.
To Make Filling: In a heavy saucepan melt the butter over medium-high heat. Stir in sugar and evaporated milk. Bring mixture to a boil and stir for 5 minutes. Remove from heat and stir in the marshmallow cream, 1/4 cup of the peanut butter, and the vanilla. Add the peanuts, and spread over the base layer. Refrigerate until set.
To Make Caramel Layer: Combine the caramels and cream in a saucepan, stir over low heat until melted and smooth. Spread over the top of the filling and refrigerate until smooth.
To Make Frosting Layer: In another saucepan combine 1 cup milk chocolate chips, 1/4 butterscotch chips and 1/4 cup peanut butter, and stir over low heat until melted and smooth. Pour over the caramel layer. Refrigerate for at least 1 hour. Cut into 1 inch squares. Store in the refrigerator.