In a medium saucepan, over medium heat, melt the butter and the 12 ounces of semisweet chocolate chips. Stir constantly until just melted. Remove from heat and let stand for 5 minutes to slightly cool.
Beat chocolate mixture with sugar, eggs, and vanilla.
Add the cocoa powder, flour and salt. Mix on medium speed until combined. Cover bowl with saran wrap and refrigerate for about 30 minutes.
Use a small ice cream scooper to scoop cookies.
Pour crushed candy canes into a small dish, press cookie dough balls into the peppermint and place on parchment paper-lined baking sheets
Bake for 12 minutes.
Let cool on baking sheet for about 5 minutes then transfer to a wire rack to cool completely.
Melt white chocolate and peppermint exact, transfer to a piping bag. Drizzle over cookies.