Prepare cake batter according to box directions.
Fill cupcake liners about 1/3 full and bake 10-15 minutes.
Remove ice cream from freezer to allow to soften.
Allow cupcakes to cool completely.
Fill remainder of cupcake liner with ice cream pressing down to remove trapped air.
Place in Freezer to harden for at least 1 hour.
In a large bowl, cream the butter and Powdered Sugar.
Beat in the milk mixing until fluffy.
Transfer the icing to the corner of medium size zipper bag, try to minimize trapped air and close. Clip a small piece off the corner to pipe.
Pipe icing around top of each cupcake and return to freezer until ready to serve.
Remove cupcake liner before serving.