In a heavy, small saucepan melt unsweetened chocolate over low heat; stirring constantly until chocolate begins to melt.
Immediately remove from heat; stir until smooth. Cool.
In a medium bowl beat sugar and butter with an electric mixer on medium speed about 4 minutes or until fluffy.
Beat in melted chocolate and vanilla.
Add egg product, 1/4 cup at a time, beating on high speed after each addition and scraping the side of bowl constantly.
Spoon filling into pastry shell.
Cover; chill in the refrigerator for 5 to 24 hours or until set.
Melt chopped semisweet chocolate with 1/4 cup whipping cream; cool.
In a chilled small bowl beat 3/4 cup whipping cream with chilled beaters of an electric mixer on medium speed until soft peaks form.
Add chocolate mixture; beat on low speed just until combined.
Melt chopped white chocolate with 1/4 cup whipping cream; cool.
In a chilled small bowl beat 3/4 cup whipping cream with an electric mixer on medium speed until soft peaks form.
Add white chocolate mixture; beat on low speed just until combined.
Before serving, spoon semisweet chocolate topping into pastry bag fitted with large star tip.
Spoon white chocolate topping into another pastry bag fitted with another large star tip.
Pipe toppings in small puffs onto pie.