Line a large baking sheet with parchment paper.
Add the softened butter and sugars to a large bowl and mix until light and fluffy using a stand mixer or with a fork by hand.
Add in the eggs, vanilla extract and peppermint extract and stir until combined.
In a separate bowl, combine the GF flour, cocoa powder, baking soda and salt. Mix until combined.
Add the dry ingredients into the bowl with the wet ingredients and stir until a thick sticky dough forms. Stir in the dark chocolate chips. Refrigerate for 30-60 minutes (up to overnight).
Preheat oven to 350 degrees 15 minutes before baking.
Use a cookie scoop to form 1.5-2-inch wide balls. Space them 2 inches apart on the baking sheet and press down slightly with your hand. Recipe makes 22-24 cookies.
Bake for 9 minutes. Remove the pan from the oven and gently press a ½ of a marshmallow into the center of each cookie (being careful not to flatten/squish the cookie completely). Return the cookies to the oven for 3-4 more minutes until the cookies are done and the marshmallows begin to melt.
Let the cookies cool completely (either on the baking sheet or on a cooling rack), then add them to another (or the same) baking sheet lined with parchment paper to prepare for drizzling.
Combine the chocolate and coconut oil in a bowl and melt in 30 second increments in the microwave. Alternatively, use a double boiler on the stove to melt.
Drizzle some of the chocolate over each cookie, then sprinkle with crushed candy canes before the chocolate sets. Refrigerate for 30 minutes to help chocolate set. Enjoy!