Melt the milk and semisweet chips --not the white chocolate! -- in a double boiler (see Note 1) or using the microwave, stopping the microwave and giving the chips a stir every 15 seconds until they are melted.
Place the noodles in a large bowl. Pour the melted chocolate mixture over and stir to combine. Add the white chocolate chips and the peppermint bark, and stir and toss until everything is evenly combined.
Drop the mixture by tablespoons onto the prepared baking sheet. Sprinkle the tops with the crushed candy canes. Allow to set (in warmer months this is best done in the fridge, though let them sit at room temperature for several minutes before serving).
Notes
Melting Chocolate Without a Double BoilerIf you don’t have a double boiler, you can make one by nestling a metal or heatproof glass bowl over a pot with a bit of water in the bottom — bring the water to a boil, and stir the chips frequently until they melt.Crushing Peppermint BarkTo crush the peppermint bark, break it into pieces and put it between two pieces of parchment. Roll a rolling pin or a wine bottle over it and give it some gentle wacks until it is crushed but not pulverized.