PREHEAT oven to 350°F. Beat butter and sugar in large bowl with electric mixer on medium speed until light and fluffy. Add flour; beat until well blended. Press firmly onto bottom of ungreased 15x10x1-inch baking pan. Bake 15 minutes.
MEANWHILE, place caramels in saucepan. Add 1/4 cup water; cook on low heat until caramels are completely melted, stirring constantly. Gradually add to eggs in medium bowl, stirring beating wire whisk until well blended. Stir in peanuts; pour over baked crust. Sprinkle with marshmallows and chips.
BAKE an additional 8 to 10 minutes or until marshmallows are lightly browned. Cool completely. Cut into 36 bars.
Size It Up: Sweets can add enjoyment to a balanced diet, but choose an appropriate portion.