Stir together the mashed potatoes, butter, peppermint oil and powdered sugar to form a thick dough. Just keep stirring till it all becomes one big clump. Use a spoon or ice cream scoop to put a teaspoon at a time onto a parchment paper lined cookie sheet.
Push down the dough into small patties and place in the fridge overnight. (Or freeze for an hour or so).
Melt coconut oil (or palm shortening) and chocolate chips in a pan on the stove. Once melted, dip patties into the mixture and coat with chocolate. [I didn't have quite enough chocolate to cover all of them, so I left some without their coating. I'm actually really happy with how they turned out too, but you can always just add more chocolate.]
Smash up candy canes (a great job for any young helpers in your house!) and sprinkle on top.