Place candy canes into a ziplock bag (I usually double bag because some bits can poke holes in one bag). Using a kitchen mallet or rolling pin, pound on those candy canes until they are crushed into tiny bits.
In a heatproof bowl, melt the white chocolate in the microwave in 30-second increments. Whisk smooth in-between, and continue melting until just smooth. Do not overheat the chocolate or it will seize up!
When the white chocolate is nearly all melted, stir in the crushed candy canes.
Spoon the mixture into each candy mold, carefully ensuring that the white chocolate covers the entire bottom surface of each mold and goes slightly up the sides (but do not fill to the top of the mold!). Place the candy mold trays aside in the refrigerator to let the chocolate set.
Melt the dark chocolate in the microwave at 30 second intervals until just melted, stirring in between intervals.
Take the candy mold trays out of the refrigerator and then carefully spoon the melted dark chocolate over the slightly chilled white chocolate mixture in each mold.
Place the candy mold trays back into the refrigerator until the dark chocolate has hardened. Take the trays out, flip over onto a plate or other flat resting surface, and gently push out the chocolate snowflakes. If the chocolate is completely set, the shapes should pop right out as soon as you flip over the trays.
Notes
For the chocolate, you can use bars of fine chocolate like Lindt, but chocolate chips will work too. Keep it refrigerated until you are ready to serve at your holiday party or until you're ready to give as gifts. I place them in the decorated food bags and keep them in the fridge until it's time to deliver the goods.