I am looking for the name or image of a toy from late 70s- early 80s. It was blue and my sister had pink. It looked like a sundae or milkshake and it opened into a dollhouse/playset.

HI tjhiggins - I think you're looking for one of the Mattel Sweet Toys...
http://media-cache-cd0.pinimg.com/originals/9d/13/86/9d1386094ae1b4c7036265e54aafcb2f.jpg