Preheat oven to 350℉. Line baking sheets with parchment paper.
Beat sugar and butter together until light and fluffy. Add egg and extract, then beat again until well mixed.
Add flour, cocoa, baking soda, and pepper. Stir well until thoroughly incorporated. This is a very stiff dough, it's ok that it seems a little stiffer than most cookie dough.
Roll dough into 1" balls. Coat well with granulated sugar, and place on baking sheets. Slightly flatten with your hand.
Bake 9 minutes, or just until centers are set.
Remove from oven, and immediately sprinkle lightly with powdered sugar. Remove to a cooling rack, and allow to fully cool.
Meanwhile, melt the dark chocolate.
Using a spoon, drizzle one half of each cookie with the melted chocolate. Immediately sprinkle with crushed candy cane.
Allow chocolate to fully cool and harden. Then enjoy!