In small microwavable bowl, microwave white chocolate uncovered on High 30 to 40 seconds, stirring every 10 seconds, until melted and smooth.
Immediately pour melted chocolate onto saucer.
Holding martini glass by the base, immediately roll rim of glass through chocolate to create a snowy rim.
Repeat with second glass.
Place glasses upright in refrigerator until ready to use.
Fill cocktail shaker or small pitcher with ice.
Add crème de cacao, crème de menthe, whiskey, vodka and half-and-half; shake or stir to blend and chill.
Pour into glasses, straining out ice.
Garnish each glass with candy cane looped over rim