In a large bowl, beat together the softened butter, granulated sugar, and brown sugar until light and fluffy.

Mix in the eggs one at a time, then add the vanilla extract.

In a separate bowl, whisk together the flour, cocoa powder, baking soda, baking powder, and salt.

Slowly beat the dry ingredients into the wet mixture until just combined. Avoid over-mixing.

Scoop cookie dough onto parchment-lined baking sheets. Bake at 350°F for 8–10 minutes, or until the edges are set but the centers are soft.

Remove from the oven, quickly press 3–4 mini marshmallows into the top of each cookie, and return to the oven for 1 minute to soften.

Once cooled slightly, drizzle with melted chocolate and sprinkle with crushed candy canes. Allow the chocolate to set.