Preheat the oven to 350.
Cream the butter and sugars. Add the eggs, the extra yolk, and the peppermint extract.
In a separate bowl, whisk the flour, cocoa, baking soda, baking powder, cornstarch, and salt. Add the dry ingredients to the wet mixture and stir until the dough comes together. Mix in the chocolate chips quickly, do not over mix.
Scoop with a three tablespoon scoop and bake for twelve minutes. Let the cookies rest on the pan for one minute, then gently press the tops down.
For smaller cookies, use a heaped one tablespoon scoop and bake for ten minutes, then press gently.
Melt 4 ounces of almond bark, drizzle on top, and add crushed peppermint candies.
