In a medium saucepan over medium-low heat, stir together butter, sugar and brewed coffee.
Add bittersweet and dark chocolate chips and instant espresso powder and stir until melted and combined.
Remove from heat and allow to cool for 10 minutes.
Transfer mixture to bowl of an electric mixer. Add eggs, one at a time, and mix well after each addition until combined.
Add flour, salt and baking soda and mix until just combined.
Cover and chill at least one hour or as long as overnight.TIP: If you chill longer than one hour, allow the cookie dough to sit at room temperature for 10-20 minutes to allow it to scoop more easily.
Remove cookies from oven and immediately place one unwrapped candy on the top of each cookie. Allow candy to melt and using the back of a spoon, swirl melted candy over top of cookie.
If desired, garnish still warm cookies with crushed candy cane.