1. Line cookie sheet or jelly-roll pan with waxed paper. Place cooling rack on prepared pan.
2. Trim rounded portion from top of cake. Slice cake horizontally into two equal layers (each about 3/4 inch thick). Using heart-shaped cookie cutter, cut heart shapes from cake. Place hearts on cooling rack. Set aside extra cake pieces for another use.
3. Place chocolate chips and shortening in medium microwave-safe bowl. Microwave at MEDIUM (50%) 1 minute; stir. If necessary, microwave at MEDIUM an additional 15 seconds at a time, stirring after each heating, until chips are melted and mixture is smooth when stirred.
4. Pour or spoon melted chocolate over and down sides of hearts. Refrigerate about 30 minutes or until chocolate is firm.
5. For each sundae place chocolate-covered heart on serving plate. Add scoop of ice cream and drizzle ice cream with strawberry syrup. About 8 sundaes using 2-inch cookie cutter.