Combine brown sugar and melted butter. Add eggs, soda and milk. Mix well. Stir in melted chocolate. Add flour. Stir in nut meats. Drop onto greased cookie sheet and bake at 375°. Remove from oven and put 1/2 marshmallow (cut in half) with sugar side up, on top of each cookie. Return to oven to soften marshmallow (1 minute). Remove and press down with spoon. Cool on rack. Frost with your favorite chocolate frosting.
Note: For more red color, add chocolate last.