Using the 2 tablespoons of real butter, butter the bottoms and sides of a 9x13" baking dish. Set aside.
Coat a large heavy saucepan with a little butter. In the saucepan, combine milk, sugar and 1/2 cup butter. Cook and stir over medium heat until sugar is dissolved.
Bring to a rapid boil; boil for 5 minutes, stirring constantly. Remove from heat; stir in chocolate chips and marshmallow creme until melted. Fold in caramels, cashews and vanilla; mix well.
Pour in prepared pan. Cool.
Cut in 1" squares. Store at room temperature.