COOK 2 cups marshmallows (or 1 cup marshmallows for trial recipe), semi-sweet chocolate and milk in saucepan on low heat until marshmallows and chocolate are completely melted and mixture is well blended, stirring constantly. Pour into large bowl; cool 30 min.
WHISK whipped topping into marshmallow mixture; spoon into piping bag fitted with star tip. Pipe about 3 Tbsp. whipped topping mixture onto each cupcake; top with 5 of the remaining marshmallows and a sprinkle of cocoa powder.