Preheat oven to 350°F. Prepare two baking sheets by lining them with parchment paper.
Using a double boiler method, add chocolate and butter into a heat proof bowl and place over a small saucepan of simmering water and stir until melted.
In a stand mixer with the flat beater attachment, mix together eggs and sugars, on medium-high speed, for 5 minutes.
While eggs and sugar are mixing, sieve the dry ingredients, cocoa powders, flour, baking powder add salt to this and set aside. Note: the black cocoa is mainly to give it a deeper richer colour but you can omit and use Dutch processed cocoa instead.
Pour in the butter and chocolate mixture and mix for a minute to combine.
Add your dry ingredients and mix until just combined.
Make sure to scrape the bottom of the bowl to make sure everything is well combined.
Using a cookie scoop or 1/3 cup, scoop batter onto prepared baking sheets.
Make sure to leave a lot of room between cookies because they spread.
Sprinkle each cookie with flaky sea salt if desired and bake in oven for 12 minutes.
The cookies will be lightly crinkled. Note: for larger more prominent crinkles, use a whisk attachment in step 3.
Let cookies cool completely on wire rack which will take at least 30 minutes. The cookies will collapse and have a fudgy centre.
Lay on parchment lined baking tray.
Using double boiler method, melt white chocolate. You can also place white chocolate into microwave safe bowl and heat in microwave in increments of 15 seconds until fully melted.
Either dip cooled cookies into white chocolate and cover with crushed candy cane, or use a spoon to scoop white chocolate onto half of the cookie before sprinkling on candy cane.
Lay chocolate covered cookies on parchment lined baking tray to cool.
Let chocolate cool and harden, you can hasten this by placing cookies in fridge.
Serve. Store in air tight container at room temperature for up to 3 days.
