Lisa, this was posted back in 2001 by Bonnie/Ohio as a copy of "magic shell," a chocolate sauce that hardens when poured over ice cream. Maybe give it a try?

1 pkg. (6 oz) chocolate chips
1/2 stick butter or margarine
1/4 cup mazola corn oil

Melt chips and butter together (microwave on low).
When melted, add oil.

Pour over ice cream and it will harden.