Step 1

Preheat the oven to 400°F and line a large baking sheet with parchment paper.

Step 2

Melt ⅔ cup (~3.7ounces) of the chopped chocolate in a bowl set over a pot of boiling water or a double boiler, stirring constantly. Mix in peppermint extract and stir to combine. Remove from heat and let cool a bit while you prepare the rest.

Step 3

With a stand mixer fitted with the whisk attachment or a hand mixer, beat the egg whites over medium speed until soft peaks form.

Step 4

With the beaters going, slowly mix in ½ cup of the powdered sugar, one tablespoon at a time. Beating until the mixture resembles fluffy marshmallow creme, about 2 minutes.

Step 5

In a separate bowl, mix together rest of the powdered sugar (1/2 + ⅓ cup), cocoa powder, cornstarch, and kosher salt. With the mixer on low speed, slowly fold the dry ingredients into the egg white mixture, 1 tablespoon at a time.

Step 6

With the mixer on low, slowly stir in the melted chocolate and the remaining ⅓ cup of chocolate chunks until combined.

Step 7

Use a spoon or a cookie scoop to drop a tablespoon balls of dough about 1.5-2-inches apart on the prepared baking sheet.

Step 8

Bake until puffed up and beginning to crack, 10-11 minutes.

Step 9

Let them cool 1-2 minutes on the pan before transferring to a wire rack to cool completely.

Step 10

Meanwhile, clean the bowl of the stand mixer and whisk.

Step 11

When the cookies are completely cool, place the marshmallows in the clean bowl and with the wire whisk, beat on high speed until the marshmallows begin to break down and turn to (really sticky) marshmallow cream.

Step 12

Use two forks to pull up the marshmallow cream into strands and decorate the cookies with messy stripes or zig zags of marshmallow cream. Top with crushed candy canes.