Preheat oven to 350. Grease and flour 13x9-inch baking pan.
BAR: In a large saucepan over low heat, melt butter and chocolate; add remaining bar ingredients and spread in prepared pan.
FILLING: In a small bowl, combine cream cheese with next 5 filling ingredients. Blend until smooth and fluffy; stir in nuts. Pour on top of bar mixture and sprinkle with chocolate pieces. Bake 25-35 minutes or until toothpick inserted in the center of pan comes out clean.
FROSTING: Sprinkle marshmallows over top of bars and bake 2 additional minutes. In a saucepan melt butter, milk and cream cheese. Stir in powdered sugar and vanilla and heat until smooth. Pour frosting mix over marshmallows and swirl together.
4 Points Each; 190 for Entire Recipe