In a large saucepan over medium low heat, melt butter, unsweetened chocolate and semisweet chocolate. Remove from heat.
Whisk in sugar until well mixed. Add and mix in one egg at a time to the chocolate mixture. Whisk in mint extract.
In a medium bowl, mix together flour, baking powder, and chocolate chips.
Add flour mixture to melted chocolate mixture and stir to combine.
Transfer batter to the bowl, cover with plastic wrap, and refrigerate for 2 hours (up to 24 hours).
To Bake
Preheat oven to 350°F. Line baking trays with parchment paper.
Using a 1¼ Tablespoon cookie scoop (size #50), scoop dough and roll into 1 inch balls. Place on lined baking tray, about 2 inches apart.
Bake for 8 minutes, remove from oven and sprinkle with chopped candy cane while cookies are still warm.**
Cool on baking tray for 5 minutes then transfer to cooling rack and cool completely.
Notes
*I did not use all of the candy cane for garnish. Nutrition information includes ⅛ cup.**To achieve a perfectly round cookie, place a cup over the warm cookie and swirl it around. The motion, along with the steam trapped in the glass, will form a perfectly round cookie.
Cookies can be frozen for up to a month and will last in airtight container for up to a week (although usually gone before then).
Can freeze the dough for about 30 minutes instead of refrigerating for 2 hours.
Use a 1¼- 1⅓ Tablespoon scoop (about 1⅓ inches wide) for a 1 inch ball.