To make top of candy box, place heart cutter on non-stick cookie pan. Fill cutter 1/4 in. thick with melted white candy; refrigerate to set and unmold.
To make bottom of candy box, place heart cutter on non-stick cookie pan. Fill cutter 1/4 in. thick with melted candy on bottom and use spatula to ice up sides of cutter to form bottom of box. Refrigerate until firm and leave candy in cutter.
To decorate lid of box, turn heart plaque, smooth side up. Cut a small hole in parchment bag, fill with melted pink candy and use to pipe scallop design on lid; refrigerate to set.
For candy heart decoration on lid, use XOXO heart candy mold from mega pack. Use melted red candy in cut parchment bag to pipe in "XOXO", refrigerate until set. Fill remainder of heart mold with melted pink candy; refrigerate until set and unmold. Attach to center of candy heart lid with melted candy.
For candy heart treats inside heart, fill heart molds half full with melted light cocoa melts from mega pack; refrigerate until set and unmold.
Fill candy heart mold with candy hearts, position lid and place in Valentine bag.