Instructions:
You CAN make the candy cane cookies just in one color, but if you want to be really creative, you can at this point separate the dough into two halves and then mix in a little red or green food coloring into one or both of them. If you DON'T want to do this step, at this point just take the plain white dough and roll it into four-inch strips, curve them into candy cane shapes, and place them on a baking sheet. It is much easier to make the strips by rolling them on a floured surface than it is to roll them into strips using both hands. If you DO want stripey cookies, the easiest way to do it is this.
At this point, the directions for plain white dough and swirled dough become the same again.
Before putting anything in the oven, you should have your topping ready. (The cookies have to be hot when it is applied, so don't wait until they're in the oven to start this.) You'll want to mix crushed peppermint with sugar in an even mix. The easiest way to crush the peppermints is in a baggie with a hammer or rolling pin. Round peppermints break easily if they're hit on their side rather than on their flat broad top, so stand them up before giving them a sock. After they're broken once, they crush easily. Get the peppermint candies as crushed as you can, as much like sugar as possible (though it is all right if there are visible pieces there).
The candy cane cookie dough should bake on the sheets for 9-10 minutes. Don't let them get brown. Remove from the oven, put them on a rack, and immediately sprinkle them with the mixture of crushed peppermint and sugar. (It makes this step easier if you line your baking sheets with foil, because that enables you to pluck the whole sheet of cookies off the hot baking sheet and place it in one piece on a rack while you decorate.) You can serve this with your extra peppermints as garnish on the plate!