Preheat oven to 350 and grease an 8" cast iron skillet
In a large mixing bowl add the flaxseed with tbsp of water and let gel for 3-5 minutes
Add the butter and sugar into the bowl and mix until combined
Stir in flour, cocoa powder, peppermint extract, salt, baking powder, and baking soda until everything is evenly incorporated and a dough forms
In the bottom of the cast iron skillet make an even layer of chocolate cookies. (It is okay if there are some holes)
Then sprinkle the chocolate cookie dough over the cookies and press down to form an even layer of cookie dough over the cookies.
Place in the oven to bake for about 25 minutes until dough has set
Sprinkle chocolate chips over the top of the cookie and allow to melt for a couple minutes. Then spread the chocolate into a even layer.
Option to serve warm so that the cookie is super fudge, or let cool so the cookie sets and gets a little more crumbly, and the chocolate topping forms more of a shell.
Notes
Be sure to use gluten free chocolate cookies if wanting to keep this recipe gluten free.