PREPARATION:

1. Melt chips with whipping cream in heavy, medium saucepan over low heat, stirring occasionally. Whisk in rum extract and vanilla until blended. Pour into pie pan. Refrigerate until mixture is fudgy, but soft, about 75 minutes.
2. Shape mixture by tablespoonfuls into 1-1/4-inch balls; place on waxed paper.
3. Sift powdered sugar and cocoa into shallow bowl.
4. Roll balls in sugar-cocoa mixture; place in petit four or candy cases. (If coating mixture won't stick because truffle has set, roll between your palms until outside is soft.)
5. Truffles can be refrigerated 2 to 3 days or frozen several weeks.