Bake pastry shells according to package directions. Remove from baking sheet and cool on wire rack.
Microwave white chocolate and ¼ cup cream on high for 2 minutes or until chocolate is almost melted, stirring halfway through heating. Stir until smooth. Cool to room temperature.
Beat remaining cream with electric mixer at medium speed until soft peaks form. Do not overbeat. Fold half of the whipped cream into chocolate mixture. Fold in remaining whipped cream just until blended. Spoon into pastry shells. Drizzle with melted chocolate. Refrigerate 1 hour.
To drizzle chocolate, place chocolate in a heavy-duty zipper-style plastic sandwich bag. Close bag tightly. Microwave on high 45 seconds or until chocolate is melted. Fold down top of bag tightly and snip a tiny piece off one corner. Holding top of bag tightly, drizzle chocolate through opening.
Recipe by Webicurean at http://blog.webicurean.com/2005/03/19/white-chocolate-mousse-pastries/