Mold candy hearts. Melt white Candy Melts candy according to package directions. Use melted candy to fill larger base of dessert shell mold about 1/3 full (about 2 1/2 tablespoons). Tap to smooth and remove air bubbles. Slowly press smaller top mold into filled larger mold to displace melted candy up sides. Secure molds at tabs. Chill until firm, about 10 to 15 minutes. Gently twist to unmold. Use knife to trim off any excess candy from edge.
Fill candy hearts. Prepare chocolate mousse following recipe directions. Use tip 21, cut disposable decorating bag and chocolate mousse to fill candy heart with zigzags.