In a large bowl, crumble the carrot cake with your hands. Using a spatula, stir in about 3/4 cup of the cream cheese frosting. Add more as needed. The mixture should stay together when rolled into a ball, but not be overly sticky.
Roll the cake mixture into 1-inch balls. Set the cake balls on a plate and refrigerate until cool, about 30 minutes.
In a medium bowl, add the white candy melts, white chocolate, and vegetable shortening. Microwave at 30-second intervals, stirring after each until melted.
Dip the cooled cake balls into the melted white chocolate mixture and coat completely. Set on wax paper and allow chocolate to set completely.
In a small microwave-safe bowl, melt the orange candy melts by microwaving them at 30-second intervals, stirring after each, until melted.
Add the melted orange candy melts to a piping bag or plastic baggie. (Use caution if using a plastic bag. If your melted candy is too warm, it can cause the bag to break.) Cut a small tip off one corner of the bag and drizzle the melted candy onto the coated cake balls. Top with a carrot sugar candy, if desired.
Once the candy coating is completely set, pack and store the truffles in an air-tight container.